in the casino and want to make sure you have enough left over for some "sure-thing" fun up in the room, your best course of action is to take the donation, put it in an envelope, put the envelope in the safe in your room, and LEAVE IT THERE until the lady shows up.
Good luck & have fun!!
On my upcoming trip to LV, if I have anything left over to spend in the casino, so be it. If not, there are plenty of tables back home that I can lose the same amount of money on. There are few places in this world that have the selection of such fine ladies as Las Vegas! Should be a no-brainer.
if you set up an appointment than you should put the money aside you were going to use for the appointment so you will not have to cancel. But not all guys think logically and I do get last minute cancelations.... But then again there are guys who do not pre book and win lots of money and set up short notice visits or extend their date for longer!
I guess that is Vegas for you lol
Why not find a lady who has a companionship rate?
You hand her the donation before you start gambling..
The two of you can gamble together...
Since she is already there by your side, you can't gamble away all of your money.
If by chance she doesn't ask you to pay before you start and you gamble all of your money away.. Well, you have issues. Serious issues. 
Five years ago I won $400 playing craps. When I got home I put it in a separate bank account and I've been playing with it ever since. I had it up to $1,800 at on point, but now it's down to $800. That's why I started switching to poker. When I win I dont spend it, i put it back in the account. The profit comes from the comps.
Understand the principles of "Gamblers Ruin", it's a math formula that calculate the probability of winning X dollars before losing Y dollars, and it is proven by the casinos experience. 80% of the people who go to a casino are UP 20% of their bankroll at any one time in the evening. 90% of them give it back to the casino and rest of every they came with.
In gambling terms It's called establishing "win goals and lost limits". The most effective win goal is to look to stop playing when you are "UP" 25% of what you are willing lose. So if you are gambling with $200, and you find yourself ahead $60, you make one $10 bet, if it wins you keep playing with that money until that is gone or you win another $30 or so, then it's the same plan. If it loses you stop. Take a break, play again later.
Take your bankroll and divide it up into evenings, $1,500 gives you five evenings of $300 each. Look at it as if you are fighting five battles to win a war, some wins, some looses at the end of the week you tally up what you got and put it back into it's separate account.
I did not make up these principles, they can be found in most books written by gambling experts.
Also I segregate my money according to expenses and income. Play money comes from a part time job. Vacation money comes from my regular income, gambling money comes from ...see above. That's why I'm willing to spend a couple of K on the girls, but I eat in a timeshare instead of staying on the strip and going to fancy restaurants.
Good luck
all the money management you have learned is sheer bullshit. To simplify things for you... Lets say you are going to play 10,000 rolls of the dice or hand in cards, or pulls on the machine. In this long run the casinos small edge will definately come out and you will be a net loser. The good runs and bad runs (good and bad luck as you amateurs call it) cancel each other out IN THE LONG RUN. Do you really think the cards or dice care where you "take a break" in that run of 10,000 hands. Whether you take a break at 100 hands or 1,000 hands because you are "up"? Do you think the cards care what "seperate bank account" you keep your bankroll in? It makes no difference to the cards or dice that you keep it in the bank rather than your pocket. No matter what money management techniques you employ in the long run you will come out a net loser.
For instance, the casinos would be shutting tables down when the table was a little bit "ahead". Or shutting then down when they were losing. They don't do this. No matter when they shut a table down or open it up I guarantee that at the end of the month EVERY table is ahead. In the short run (where you are at now with the relatively few rolls you have done) any casino table can be a net loser. But in the LONG RUN, which is tens of thousands of hands, EVERY table wins.
The fact that you are still up $800 is because you haven't rolled the dice enough times to get into THE LONG RUN. Once you get there I GUARANTEE you will be a loser.
You got the first sentence almost correct about "Gamblers Ruin". It's actually called "Risk of Ruin". If pure money management could actually beat the casinos, everyone would be doing it because it is such a simple concept. Then the casinos would all go broke and they would be out of business. Instead of depending on the "experts" for advice you should learn some math, statistics and probability from math books and then you could see that the "experts" your depending on don't know math either. They're are just trying to sell books to people like you.
Read about "the probability of large numbers" if you want a starting place. It says that with the casinos small edge, when you get into large numbers of outcomes the small casino edge will definately come out and the casino will be a winner and you will be a loser. And it makes no difference how you chop up the long string of outcomes (rolls of dice or cards) the end result will be the same and will fall within the bell shaped curve. Which brings me to the second thing you may want to learn, how to calculate the probabilities falling into a bell shaped curve.
According to "gambler's ruin" , a formula developed by Christiaan Huygens in the 1600's, and expanded upon with the use of matrix algebra, playing a game with a modest house advantage of less than 2%, you have a 70% chance of winning $50 before losing $200. Of course as long as the probability is less than 75%, in the long run this is a losing proposition. But the point is not to make money gambling, the point is to have fun gambling, and to be in control and not lose your session money. Money management principles can help accomplish that.
thought you were trying to say you could beat the house with money management. Of course you can beat the house at blackjack where there are not "independent trials" but not at games like craps, roulette, ect where independent trials exist.
you are defiantly right .......