Howard, yes it is insulation, a type of hard styrofoam IIRC.
Josh, Each 36" cabinet cost around $80, the top was $20 as it was a scratch and dent, stain and sealer was about $20, and with all the misc. hardware to mount everything it total right around $220. If I wasn't in a rush I probably could've built a set of cabinets out of plywood and red oak for about $50-$60 each which would've been stronger and eliminated the particle board, but I was in a rush so I chose the already completed one. It took me about a week and a half to put everything together, stain the cabinets, and mount the presses. That was only working on it about 1-2 hours a night. The staining/sealing took the longest at 4 days to do, but that was because I put a three coats of stain and three coats of sealant on it.
