Wow -two in one week, and for such little money? That sounds like some powerful Karma; the Audio Gods have been smiling on you, for sure!
Tough call on the swap - I'd check what they've been selling for on eBay and CL, and take that into consideration, especially if there is a significant price difference, but don't forget that selling one and using the money to buy the other involves more time and hassle and risk, too, so discount the figures acordingly. How badly do you want the TT, compared to the second receiver? How badly does the other guy want to make the swap? What condition are the two units in, and how much (if any) work would have to be done on them, to make them near-new again? What (if any) original documents and accessories are included? If the money aspect isn't too unbalanced, it could be a nice win-win for both of you, but I wouldn't rush into it.
Here in the local market (which may not be typical of other markets), I've seen a few more of the TTs than that receiver, and the TTs have been a little cheaper, so it might not be the best deal for you. If you can back it up with specific sales-price examples (eBay records, for example), you might make him a counter offer of a swap for the TT plus a little cash, and see what he says.
