Duplex Analysis help!!

[Rick Baker]

I have an opportunity in a great neighborhood in Dallas and need to know if it is a good deal. This is a duplex in a desirable neighborhood with million dollar houses all around. The home is in good shape but a little dated but the house needs some foundation work. One side is rented for $1800 a month and the larger side is vacant. The duplex is 3871 sqft and there is an opp to sell the vacant side but continue to rent the occupied side. Comps show that the other side could sell for around $375k and I can get the both sides for $505k. Thanks for any insight you can provide.