If someone doesn't have a bank account they should expect to pay a fee to whoever is doing the money exchange. I have a bank account and they dont charge me - BUT I do get some 'promos' because I maintain a 'minimum balance' as defined by the bank.
I personally have no illusions that everyone is not in the US.
If you're paying for a check to be deposited you must be talking about a check drawn on a foreign bank sent through the mail.
Costs me $8 to deposit each International Bank Check in US dollars. Australian banks to do not accept US bank checks or US money orders. Hence the importance of Paypal.
It all really depends on your click through rate. The ratio of people that click to the people that view it. So if you run a site for a bunch of people that aren't really consumers, or don't really care.. like me, it's kind of uselss. It all depends on your audience.