Pretty tough to give pond estimate so many factors. My advice get several bids from reputable pond builders. We have not been involved with any 2 acre ponds that cost less than $25,000. Cost of diesel fuel has made it tough to build for less than that even in what sounds like a good site.

Depends on depth but typically if a 2 acre pond is 8 foot avg depth I would say a two diffuser system with 1/2 hp is more than adequate and looking at under $2,000. Not neccesary but great investment for your water quality and fish.

Greg Grimes
www.lakework.com