You can expect to pay upwards of $40k for a decent SE these days. A nice driver can probably be had for under $20k though. If you open up to the '76, '78 and '79 SE's you have a much better chance of finding a nice one at a decent price.
IMO, the SE package was probably the nicest looking Trans Am ever built. Maybe I'm biased from growing up on S&TB, but a black TA with gold trim, especially with T-tops just looks awesome. I like them best in this order, '78 WS6 SE, '77 SE, '76 SE, '79 SE, then the '80 and '81 turbo SEs. Granted they all look really good and I'd be happy to have any of them. I'm still kicking myself for selling my '77 TA. It was an original starlight black car with the SE stripe kit added.
If you want something you can drive and enjoy, then an SE clone is probably the way to go. You can have the exact same look without the price. From a performance standpoint the SE didn't add anything you couldn't get on a regular TA. But if you just have to have the real thing, then you're going to pay a bit more for it.
I never quite understood the tremendous price gap for what amounted to an appearance package, but then again, that's all the Pace Car and anniversary edition TA's were for the most part too, except the '89 Turbo TA, which offered the Buick 3.8 turbo engine which wasn't available on any other TA.
Here's a gorgeous '78, but it ain't cheap either.http://phoenix.craigslist.org/evl/cto/3638369674.html