R7 265 should be able to max guild wars 2. People with GTX 560s and 560 Tis are managing it so Pitcairn should be fine.
Stock? You're funny man. It was in stock for about half an hour. Mind waiting another month till it comes back in stock? In other news, some R9 270s are back in stock here in Canada at NCIX for around $210-240 which is not a bad price considering where the R9 270 and 270X once were at. I would say just go ahead, pay the $220 for a decent GTX 660 (Asus, GB and MSI are all good just don't settle for the shitty EVGA SC that uses reference shroud and goes for $240). It'll serve you better than the R7 265 and GTX 750 Ti and if you're lucky, you might pull a lead on the R9 270 with good drivers.
With games like GW2 you don't need anything higher like a 660 Ti or a 760 really. Though if you plan on playing other games in the future (Titanfall, anyone?) a GTX 760 might be a good choice if the stupid prices will come down for once.