Yes, though there's an Android market. The Samsung GPU helps with games -- though it never goes from playable to not playable, since even the Playstation phone will be slower than the Samsung -- and the Super AMOLED screen is always a plus. I was linking to new in box eBay auctions -- you should have full manuf. warranty, plus eBay/Paypal is quite buyer-friendly if there's an initial screwup. But a smart HowardForum guy may be able to give you the phone pre-unlocked with Froyo (the latest OS, not official yet on the AT&T Captivate), etc...
The thing is, AT&T is a huge customer base, so there's a lot more Captivates floating around than any other 850/1900 Android. If you're interested in Apple, wait for the flood of iPhone 4 users who flee to Verizon next week.