The price of the sunmate is about 25.00 and you can do two seats. The Pudgee is very expensive and made to order. I paid 68.00 shipped for a 18x18, they may allow you to buy a smaller piece, give them a call.Great mod. I feel the same way about my gel seat, and it looks like you've fixed the issue.
Do thye sell the foam in small enough sizes to not be super expensive?