So here's teh deal w/ buying it back.
The insurance company, by law, must give you the option of purchasing the vehicle back from them at 10% of the value.
What is the value? Well it's what they are giving you for it. So what you want to do is to convince them that it is worth a pretty penny. Having pictures like above, that show its condition, help out a lot. What you need is ads from AutoTrader etc taht show the *actual* cost to purchase a similiar vehicle in similar condition. They will lowball you and say like $1500 or 2k at first, don't take it! Push them with actual ads etc, might get that up to 3k or so, who knows. They have to give you the 3k+tax+title fees.
THEN tell them you want to buy it back as salvage. So that would cost you 300, you get a check for 2700+tax,fees etc.
Now that I've said it, salvage value might be 20%, I can't remember, somebody chime in here. But the point is, don't worry about teh salvage value, focus on getting the real value first. And they won't consider all teh extra stuff in that so you migh tas well take it back anyway.
Remmeber - until you sign anything, *you* still own the vehicle and all of its contents.