There are a lot of factors that can weigh on the answer to your question. Who is the investor? I have one right now that is FHA. FHA did an appraisal and came up with a price. FHA also says they want 88% of the appraised price, period, no negotiations. I think the appraisal is too high. It took me WEEKS to get them to agree to do another appraisal and, if it comes back at the same price, I am just stuck with it.
I have had similar problems with Fannie Mae and Freddie Mac. I would have my agent get as much information from the listing agent as possible. I am sure the owner and listing agent want to sell the home as much as you want to buy it. It's very difficult these days to "low ball" a short sale, they banks in some areas are just not discounting them any longer.
I will say this, the fact that they countered with full list price is a pretty good indication they thought your offer was very low. Do your due diligence, look at recent sales of similar homes, factor in any repair costs and make your counter offer accordingly. A reasonable discount will probably be accepted but if you are too greedy, yes, they will lose the house. My buyers did and in my opinion THEIR offer was very reasonable.