we just had carpet removed and hardwood installed in our three bedrooms (+4 closets) and hallway last week (about 800 sf). The person who gave me the estimate gave me one price, then checked under the carpet and saw that the subfloor was particle board so he added another $1500 to the price to cover removing+hauling the particle board and installing plywood+plywood cost. When the guys arrived to do the work, they realized that there was plywood underneath the particle board, so all they had to do was remove the particle board (not install more plywood). They told me the company would reimburse me for the rest, so after a couple of phone calls, somebody finally dealt with the issue and told me they would reimburse me $500. Does this sound reasonable? It seems to me that the price of plywood+labor to install it would be more than that. In fact, I would imagine that it might be half of the total (remove+haul particle board+plywood material+plywood installation). Can anyone give me an idea on this? If this helps, we're located just outside Boston, MA.
Thanks,
CC

I charge $1/sf to rip up particle board plus a disposal fee probably $150.00 so that part is`about right. They would have screwed themselves on the plywood as I charge $40/sheet so that would have been around $1,000.00 for a total of around $2,000.

So that sounds like removing particle board + hauling would cost about the same as plywood + installation. Unless, the company was planing on using a cheaper plywood. I checked the home depot site and it seems that prices can vary a lot. They did tell me that the $1500 was a discounted price because of the rest of the work (remove carpet and install hardwood floors). I just felt that since they didn't need the plywood, I would have at least $750 credit. Anyway, it seems that the $1000 I was in fact charged for removing particle board is reasonable so I guess I will leave it at that.
Thanks a lot for your help Jeff.

Jeff, is that $40 bucks a sheet installed price

yes $40 supplied and installed. I shoot it down with a framing gun and ring nails.