Analysis to sell duplex

[Michael Kaminski]

Looking for a sanity check on my analysis.

The critical background information is that I have a duplex that I owe 125k on and is worth about 460k. It nets ~ 21k a year and is in an A class neighborhood with great appreciation. The property is right on the brink of needing a large cash injection in remodel costs.
We are looking for our "forever" home and looking to make the best use of the assets that we have. So the age old question sell it or keep it. If we target an 800k property our payment is 5300/month. If we sell the duplex assuming it costs 15% to sell and another 15% in long term capital gains that leaves ~228k. There might be some depreciation recapture I'm not accounting for. Applying that 228k to the 800k brings the payment to 3800/month. That is a 1500/month savings in monthly payment. Technically that is 250 less per month if I hold onto the duplex but to me 250/month gains will be quickly consumed by the coming remodel. 
I think the data says to sell it but what does the greater community have to say?