I have a '91 H23, bought in May. I like it, for a glorified day-sailer on a Lake. Wouldn't be too comfortable for extended crusing, though.
$1400 with decent trailer (if it is) and motors (if either works reliably) sounds like a very good deal, if the boat is serviceable. For the most part, I had seen prices from maybe 2500 or 3000 up to as high as 8000 or so (for whihc I'd expect a really pristine boat). You may want to hire a surveyor, I'd guess $300 or so?
Tough to tell from that pic, but the later 23's have a 2' 3" draft winged iron keel (fixed). I think the earlier models, don't know from what year, had a keel/centerboard. My '91 is fixed iron keel (that I had to do a lot of grinding and sanding on, to remove sacly rust and flaking paint, when I first bought it).
Does it have a jib? I think you'll need one, and that could be pricy if missing.
Other than that, how much do you know about glass boats in general? If you feel reasonably sure of yourself, just go through it wiht a fine tooth comb - keel bolts, all bilge areas, look at wood for signs of water incursion (mine had wet plywood bulkheads in the under-berth storage areas on the aft stbd side, for example, as prev owner had let water collect in cockpit and cockpit drain was clogged), stanchions, etc.
I don't know of any specifically common problems, other than to look at all places where there is a hole through the deck, including screws.