csullivan, I'm an amateur ponder.
15 acres is a great sized pond. I'd call it a lake if it were mine. Anyway, I think you could grow largemouth bass in excess of 8-10 lbs. if you started a management regime specific to a goal of lunkers.
I have a 6-7 acre pond in PA, and I have numerous 4-5 lb. largemouth, and I'm not really managing the pond for lunker largemouth. We have less of a growing season up here also. So I believe you in Texas could make it happen.
I'd also fish the place very heavily prior to making any immediate changes. I'd fish for all types of species to try to get my own picture of what's in the pond. The previous owners of my pond told me what was in the pond, and their info. turned out to be accurate, just not accurate enough to make decisive pond management moves. Only until I fished it myself did I get the full picture (and of course finding this website).
Good luck in closing the deal.
