Ugh, looking for bunk beds

I'm finding some pretty good prices through eBay on the bunk bed frames, but the dang mattresses are outrageous!! And, I have to have 2 for the bed. Michael isn't happy about spending money, but I keep telling him that at least I have the frame for Ari's big girl bed and we can use the mattress and box springs off of Joshua's current bed. We need the bunk beds in his room so he has more play space and then Christian will have a place to sleep when he visits. I'm getting a little impatient about getting it now that I did get the go ahead from Michael.