You shouldn't have any problem finding something you'd like then for that price. There is quite a bit to pick from. Thats what I did with my boat, Found an older couple that owned it and barely even used the boat and decided they wanted to buy a pontoon boat, so although my boat is 5 yrs old, its still like new...and I got it from a great price.
Mine is a HP170...which are actually 17'4", and the HP's have a little wider bottom than the Eagles(56" compared to my 60") which i'm sure makes them a little more stable and I believe they are a slightly deeper as well. They also have HP180 which you could look at too if your wanting something a little longer. They've got Hp200's too, but you'd probably step over your price range with one of those.
G3 also has their new Eagle 170's and 180 which have a 58" bottom compared to the last models which were a 56"....I believe these are the ones that are gonna be replacing the HP's, I think. They are discontinuing the HP's after 2009....I believe i'm telling you right. G3_Guy can tell you more about it as he is on their Pro Staff, so He could give you any info wanted on G3's.