Is a 480 with freesync really going to be a better gaming experience than at 1080 without it? I guess I'm living in the past but plain old 60 hz on my Dell 2408 (with a 980ti) seems fine to me.
1080 would probably be better if you buy and hold. But its a much better idea to not buy and hold right now given his situation, but instead get the RX 480 and sell when Vega drops for very little money lost to depreciation. Vega being the GPU you hold and RX 480 just a stopgap. Terribly wasteful to get a nice $1000 freesync monitor and then not use Freesync IMO