We purchased a really top quality foam crib mattress from Verlo Mattress Factory (verlo.com). They have stores in 9 states. Since we live close to a store (near Chicago), I just picked up the mattress when I was out running errands. It took them 3 days to make it for us. But this is the same quality mattress we have on our own, king-size bed. PLUS it was much cheaper than the Colgate crib mattresses. With tax, I believe we paid about 95 dollars for our crib mattress. I can't speak for delivery charges on this, but our family has been satisfied Verlo customers for years. Each mattress is custom-made to order.
I'd love to see you consider Verlo as an option in your next edition!