My proposal for Open Problem Garden

I’ve sent to personnel of Open Problem Garden the following proposal email:

Please add in each problem page a PayPal donation button. The money
collected for a problem should be directed to the person which first solves
the problem.

One additional advantage is that this would provide a way to sort problems
by importance: most funded problem are these which seem most important.

This way your site would additionally become a central hub of math prizes.

I think, it is a very good idea.