Should I Sell My GTX 1080 Ti?

I have 2x EVGA GTX 1080 Ti SC2 with 10yr warranty (non-transferrable, but 3yr is).

I'm not currently using one, but I do have an SLI mobo I could start using for my system in my sig.

I'm actually needing a better monitor. I'm currently using a 24" 1080p 144Hz FreeSync monitor and a 28" 4K 60Hz FreeSync monitor. RX Vega is disappointing. So, with the RTX/GTX 2080 Ti releasing, what should I do? What would you do?

I don't actually have to sell one to buy a monitor (I was looking at 1440p 144Hz G-Sync $600-700), but most people say SLI isn't really worth it. But what if I already have two GPUs? Or is that still too much money to be put in to a gaming system that is for casual gaming? I'm not made of money.

Suggestions please.
 
Solution
Buy the monitor. Try it with a single card and with both in SLI(assuming you PSU can run both), if you don't see much difference sell one of the 1080tis.


Hmm, 32" would be nice. I was looking at a 27" IPS 144Hz G-SYNC for around the same price. I'm now wondering which would be better?



I like both answers. I suppose the best way to figure out what I prefer best is to buy the monitor and test everything, then get rid of whatever I don't need.