There are a couple things that you could try to do to help in a pre-emptive sort of way. The first thing is that comps are comps. Get your old realtor to send you comps for the area that will most closely match yours. Try to find out exactly what the situation is with the comps, condition, etc. If you could somehow show that the comps were lower for a good reason then that will help. Note that a good reason is not, “it was a foreclosure or a short sale”. It has to be tangible like the home was a P.O.S and it was a foreclosure and it was a cash deal. The could be environmental differences as well, street noise, busy front street, or the neighboring home is a crack house, or the home had unpermitted additions, etc… None of this gaurantees anything especially if you get a crappy appraiser but it shouldn’t hurt things. The broker will not help at all so don’t rely on him. Also if you have done upgrades that are major, that is over several thousand dollars then those should be pointed out and if you have receipts all the better. However if you have plunked 2 or 3 thousand here and there a few times, chances are that will not help alot.

All this legwork may not help at all but it shouldn’t hurt. Don’t follow him/her around and pester them to much, wait until they are done and then bring up your points. If you have data/notes to give them about the comps feel free but keep it brief.