Before you plunk down $2500, do some reading here. The information may not be as well organized, but its a lot cheaper.
What have you done so far to close this deal? Do you actually have a seller who needs to close a short sale? Because if you don't, the odds of you 1) finding a seller, 2) getting all the paperwork together, 3) getting the bank to approve the closing, and 4) getting the closing done are essentially zero. If you're through the first three steps, you might get the fourth done in 20 days, but even that would be a very speedy closing for a bank. Step 3) can easily take months.
From your post, it really sounds like you're just getting started. You should have a list of buyers, not just a buyer. Because it takes so long to get an approval from the bank, its not really worthwhile to present a deal to your buyers until you have to approval. You will want a pipeline of multiple deals in the process. As soon as you get an approval for one, pass it to your buyers.
So, the basic steps are:
1) Market for sellers
2) Work with the seller to get the package together for the lender
3) Work the process with the lender to get the short sale approved.
At the same time, market for buyers. Build up your buyers list.
Once you get an approval from a lender, pass that deal along to your buyers.
Once one of the buyers accepts the deal, proceed to closing.
I assume you're aware of the issues like banks refusing to allow assignments on short sales, so you have some other method to proceed with the closing.