Crib Mattress Recommendation for Grandparent's House

Hi All,

I am purchasing a full-size portable crib to keep at my parent's house and looking for a mattress. My 15-mon old will probably only sleep in it for 6 weeks a year, so I don't want to spend too much money (under $100 would be great). Does anyone have any recommendations? We have a Naturepedic Foam mattress for his crib at home. I would love to stay with foam, but so far I'm not finding any in this price range. I also don't know too much about coil mattress. Any advice would be extremely appreciated!

Thanks in advance!

We have the cheapest Sealy Soybean foam core mattress and I am very happy with it. I am fairly certain I paid less than $100 for it a year and a half ago, but the lowest I'm seeing one right now is $119 (both Target and Amazon). I don't know if it is the exact same one we have.

Ikea. $30-40.

Thank you!