First commercial deal: Corner lot of two highways with old buildings? How do I know it's a good deal

[Mark Bradford]

Let me lay this out for you. Small town in the Midwest as two highways (2 lane medium traffic flow) that intersect at the corner of its town. One corner has a car wash, one has a well est. church and the other has an abandoned house.  Sitting on the last corner is a large grouping of lots. Along the more major highway we have 4 lots (2 are just a gravel lot. They were a gas station at one time.) 2- have a old house and garage that have to be torn down.  Now along the back of these lots runs one more lot that has a building (one story 30x60) in need of major repair but it can be saved.  Along the back of that lot is 4 more lots!  3 have one house with a possible rent rate of $650/ month, the other lot has a house that rents for $300/ month but it looks very poor (but it is lived in).  So if you are still following this make a section of land with two sides on major highways and one side on a regular side road of small town USA. About 225' x 300' lot size as one.  

Now the real question is: If it has been for sale and empty for 5 or more years how do you put a price on it? Is it valued at the price of the livable homes? Is it valued at the price of the livable homes minus the cost of demo of the other buildings?  Any help is very much welcomed!   Thanks