If the 1 acre lot has such big trees I don't thing we would be limiting the saws to just 50cc class saws. I am not saying they wouldnt be a better saw, but for sure are'nt needed, then there is wanted.
I am just saying you never know, and he wasn't specific except wanting new probably and around the size and pro quality he mentioned.
I know what you are saying and a $175 brand new 50cc Poulan PP5020AV would most likely work for him as well, albeit heavier than a pro husky/stihl/whatever. All sorts of guys here have them now and pretty much all like them. One of the best cut for the buck deals out there now.
When I go out wooding I typically haul around five different saws with me, small to large, just because I can and it makes it easier to size to the cut, plus no dorking around in the field with sharpening chains, etc, at least most of the time. Usually two smaller saws at around 40cc class, two mid size 50 and 60,, then one larger than that. Works for me, although most times I could get by with a 60 for everything, I like larger for felling and base log bucking, and much smaller for light trimming. Mid size does most of the branch and smaller end of the log bucking.
I have done it a bunch, but really don't like cutting from two sides to make a bucking cut.
*shrugs*
If the OP hangs around here he will have multiple saws soon anyway, pretty much near always happens.