We are visiting my parents for a month long trip. There will be future long trips within the next few years. DD is 2 and sleeps in a crib. DS is almost 5 months and cosleeps but will be transitioning to crib eventually. I would prefer an organic mattress for the used crib we will buy at grandparents'. I saw a used Naturepedic one in excellent condition for $125. Is this something I should consider or is it too much money for a short time? I am really debating this price wise. I don't know if grandma will shell out this much money for a crib mattress and she still has to buy the crib (which I am scouting around to get on CL for under $75).