I own a 4 plex row complex 1890 two commercial on bottom and two residential on top.

One of them a long term tenet. That is signing a lease for 10 yr soon. Rents below market vs other tenants.

1-3 700,700,650. 4th is 475.

Taxes 675 a month

Mortgage 97500.

If the 4 tenet would buy there spot out for 100k would this be a good idea. Pays off existing loan.

I then could get a equity loan to buy other property?

I would net about 400 more with loan paid off.

Any thoughts out there?