May want to hold off for a bit. A modular expedition roof might be coming to market. Check out the jeep forum for information. Probably still be around the 15-1800 mark if it comes to market. I do like that its modular though.
If you can wait the price of jeeps and their parts has a direct correlation to the weather/season. My jeep was 4k cheaper when I bought it in Dec of last year than what comparable jeeps sold for in March and April of this year.
I bought my hard top in the spring, the guy had been trying to sell it for over 2 months. I got it for 800, just wait and watch craigslist. Use a craigslist search engine (will allow a larger radius of search) and search the farthest you are willing to drive. I used 200 miles.
I have a 2005 LJ Rubicon.
Just be patient, it will pay off in the end. And no, I'm not selling my hard top.