Well, it's funny to you

Because you'd need to pack on 25 lbs just to make a buck.  BTW, I'm no longer anorexic.  

Speaking of paying by the pound..

I went to one of my favorite Chinese restaurants,  had a fantastic meal and paid $5.99 per pound.
My total bill was $9.55. How much did I eat?

At first, I thought the OP meant that providers should charge hobbyists by how much the hobbyist weighs. (Some stores charge more for XX+L clothing than the same item in S-M-L-XL.)

Then, there was a reply to Tasha Vegas that sounded like some people thought OP meant hobbyists should have to pay according to how much the provider weighs. (I'm for that! The lower the better!)

So even though I'm confused by what was intended I think, to be fair, you should really use BMI (body mass index) instead of weight when determining rates.