We've bought a couple of 2bd plat annuals in the last year. The Golds are in the 12.5-15k range as GregGH mentions, Plats are in the 22k-24k range. "Retail" is 2x-2.5x those numbers.
Betty/Triwest had the first, and the closing was through Smartchoice Timeshare in AZ (authorized broker). All went smoothly.
Judy Rulli at Smartchoice had the second listing and (obviously) did the closing.
I really enjoyed working with the Smartchoice folks; they'll tell you the current
market prices if you call and ask them.
www.timeshareaz.com is their website.
The only thing you lose on resale through an
authorized broker is the ability to convert to hotel nights (not a good trade, anyway) but without the authorized broker you also lose the ability to trade into Scottsdale (easy) or other FS fractionals (difficult). There's no real premium paid for buying through an authorized broker and I found they had a good working relationship w/the Four Seasons Owner Services people that greased the wheels for a quick and seamless closing both times.
The annual fees are around $2k and trading a 2bed is often a trade down (and makes no financial sense), generally; however, a 1 bed and even a studio at FS will sometimes pull a full 2 bed somewhere very nice (Westin Kierland, for example), so if you did a lockoff and trade you'd end up with 2 phenomal weeks of vacation. That said, our plan is to stay at our place at FSA for both weeks we own (we purchased the 2nd week the day we finished our first trip there on our original week, it was such a great place).