You have been more than kind. In his position I would immediately assume the 400 surcharge for prior cancellations is now forfeited. If you still wish to see him and are willing, a creative and rather magnanimous solution might be to credit the 400 remaining on his "account" as 100 dollar deposits on four future appointments. He then would have to make and keep all four appointments to receive full credit.

$400 for previous cancelations is gone.  
50% fee for last minute cancelation.  $200 of the new appointment is gone
$200 can be rolled forward to deposit for a new appointment in addition to another $200 from him (total $400) or more in this case  
A note that any future cancelations would forfeit 100% of deposits and will be blocked.  This isn't fair to you and is loss of income

Four last minute cancellations is more than enough chances.
You keep the money and let him kick rocks, as nicely as you and Ms Betty can tell him.

you're too kind

You've been too generous in giving him 4 chances.  I wouldn't blame you if you decide to not give him another chance and keep the payment for all the inconveniences he caused.

In my years ago review of you I said that if there was a teenage boy that needed to be "initiated", you'd be the one that would be ideal to do it.  You are kind and caring, and that's the root of your question here.  This lad seems to have a serious inner conflict problem - wanting to see you as a fantasy or desired reality and then last minute panic and cancellation.  Could be fear of failure or some other inner demon - who knows?  But ........ it's not yours to resolve.

So this is a serious moral dilema, you've been extremely gracious with cancellations and time wasted. A death in the family can easily be proven, a fair and partial accomidation would be, show you the obituary, he's been screened so you know his real info anyway...upon showing that he can reschedule at no additional expense. Otherwise all is forfeited. This way you are not being a total heartless money grabber (as some might would see it) and it puts the burden of proof on him. I know just how caring a person you are and this would alleviate some of that "guilt" you may have.

This guys kink is not seeing you.  The adrenaline rush of working up the nerve to
call and make an appointment.  The anticipation and anxiety leading up to the time.
The overwhelming guilt as he jacks of just before no showing.

different strokes for different folks as Confusius might say...

accept the money for the missed appointments.  I wonder if it's the same guy that used to book 3-4 hr appointments with me.  He would get there and start feeling very guilty and leave, but always paid my full rate.  A year would go by and he would do it again.  I really believed he loved all the emailing and excitement leading up to the appointment.  That is what got him off.  

one of our next appointments, we should do a double again with Ms Ginger at the suite with a hot tub.  That was so much fun for your birthday!!  Big Hugs, looking forward to seeing you later!  Big Hugs, Maddie

I just love that idea...   Ginger we will be in touch.

Yes Please !!! I'm still around, just a little more UTR these days A MnG sounds great, hopefully I'll be able to make an appearance.

I’m interested in more providers opinions. Great question regardless. Life happens & people, do die. I would have some empathy. He obviously sent $800 as a sign of good faith, so have some faith in him. I would give him another opportunity. If you didn’t have to get a hotel, or have any out of pocket expenses for his last unexpected cancellation. Assuming you were not greatly inconvenienced.

I would expect you have made your decision already.

Or Confucius might tell this bloke "to sh!t or get off the pot"....

I think if he sends $400 every time he cancels just accept the money…this happened to me quite a few times this year…maybe just have him cash app it before you schedule the appointment that way you do not waste your time and if he can’t make it you are still ok

You owe him nothing.  He has taken up your energy and time in just booking and canceling multiple times. Not to mention he canceled last minute which I feel your entitled to keep the complete total without judgment. You did your job and he misused his time not you.