Continuity mistake: At the end, Pacey carries Joey upstairs and lays her on his bed because she is drunk. In one shot of Joey, her hands are up by her face but the right shoulder of her sweater is slipped off her shoulder, revealing the strap of her shirt underneath. The next shot of Joey, her left hand is still up and her right hand is down, but the right shoulder of her sweater is back up in place. It was too fast for her to fix the sweater herself, and her left hand hasn't moved. (00:40:25)
Continuity mistake: When Joey and Pacey are sitting on the bed talking during the party, there is a shot where Joey is looking to her right, directly at Pacey. The next shot of her, she is suddenly looking down and completely away from Pacey. The transition is too fast to be realistic. (00:16:55)
Answer: It's the same apartment Joey had in NYC. Comparing it to the beginning of the Finale; you can tell it's exactly the same location, furnishings, Plasma TV etc. Apparently Chris was only living with her at HER apartment, and now Pacey has taken his place at the end. I guess this implies Pacey successfully started his own restaurant business in NYC as he had dreamed, to be with Joey.