Your buyers agent should provide you research required, determine what is best interest for all parties. Each property stands alone when submitting a valid sales offer. In some instances we instruct our clients place an offer over list price secure winning bid.
Not all offers you place on a short, foreclosure you might not even have a response from bank. I have been listing/ buyers agent
Lynn911 ~ National Featured Realtor
A short sale doesn't mean cheap. Even in this market, the property will not sell for an absurdly low price. However, short sales can mean a good deal for the buyer, and even the seller. Short sales though, are always carefully reviewed by the bank, and even a full price offer may not be accepted.
When making an offer, ask your realtor to run comps on the property, and base your offer on what you can afford, what similiar properties have sold for recently, and be ready for your offer acceptance.
One tip for your and your realtor to consider, a short sale offer isn't "better" because it is for more money. I have had many short sales sell to lowest bidders because of things like, short escrows, large deposits, or all cash offers. There are many factors to take into account when deciding what price to offer, ultimately it has to be based on your desire to own that home.