The fact that utility connections are in place and available has some value but the actual value of a "foreclosed" lot will minimal difference compared to non-foreclosure lots. One of the things buyers of foreclosed home have in their favor when seeking good value is that many of these distressed homes have been vacant, neglected, and come with issues...some easily seen while others are near invisible. Buyers under these circumstances should be able to expect value adjustment considerations.
On the other hand, when considering a "vacant lot" there is little risk on the part of the buyer and therefore less of a price consideration.
Hope this helps,