Hey Pickpocket,
I live in Houston, too. Whereabouts are you?
Me, if I were to pay $1500 for an XS it would have to be in exceptionally nice condition. That's on the high side of the value for an '82 Heritage Special, and likely the reason why the guy's been trying to sell it for 8 months.
A couple years ago, I picked up a '70 XS-1 basket case and a '78 E standard for $500 for the pair. The '78 wasn't running but at least had good compression. I kinda felt like I paid too much for the pair, but then I was able to sell off most of the XS-1 parts, and by the time the dust settled, I'd made $50 profit on the deal, so I got the '78 for free. And it was the one I was after anyway for a cafe project.
I bought my '81 SH, a runner in decent shape, ten years ago for $600. It had a couple of issues, which was why it was "only" $600, but they were easy to fix. I'm thinking about selling it. It needs a new rear tire and a battery, and if I do put it up for sale, I'll be asking $1200 obo for it (with the new tire and battery of course). Here in Houston, I feel that price is fair for a running XS650 that doesn't have repair issues.
Deals are out there, you just gotta be prepared to jump on them when you find 'em.