In addition to the typical 2-3% (prepaids, tax stamps, etc) you may find that you will have to cover the expense of a survey and other items that the seller would traditionally cover, but may be unwilling to. A closing date can also be somewhat unpredictable, making financing deadlines and rate locks more challenging.
Best of Luck
Keller Williams Chicago Consulting Group
With a short sale, the seller is not getting any money out of the deal so I don't think they would be too keen on helping with closing costs.
BRC Realty Group