All of the answers below are very good advice. However, no one has addressed the fact of whether or not the lot is conforming to local zoning codes. If for example, the minimum lot size is 100 x 125, you will not be able to build on the lot without first obtaining a variance. There are also rules on the percentage of area a structure can occupy. You also mentioned there were no improvements on the lot, you will then have to seek relief from installing curbs, sidewalks etc. Call your local zoning officer and inquire about set backs, frontage requirements etc. Obtaining variances can be costly and will add to the cost of the lot. Good luck.