To me it only makes sense if their bids are lower than the other contractors that already build in their margin to the quote.

I just got a bunch of bids for a small roof leak and found American Classic and Grand Rapids Roofers to be the most competitive.

Im able to get that unrepresented buyer to bid against themselves, get them to waive contingencies that no one represented by their own agent would waive. 

If I go to the sheriff sale at the courthouse and bid $120K, does this go towards covering all of the liens in order of priority with the lowest priority lien-holder left taking the loss?

Personally I would walk it with him, create the scope of what needs to be done and have him bid that verse expecting him to bid what you want.

"Real Estate Commission Rebate Program"Pre-arranged and in place for pre-approved borrower/buyer clientsGood Faith Bid for a Purchase Price of: $500,000Listing Pays: 3%= $15,000 / Rebate to Buyer: $12,000Rebate to be credited at closing as follows: Closing Cost                         $ 8,000Home Warranty                  $ 500Attorney Representation  $ 700 New Flooring$New Window Treatments$New Windows$New A/C System $New Appliances                   $2,800Hurricane Generator$ Other: $_______________________________                                    $ 12,000 Rebate TO BUYER

For simplicity, say winning bid was 400,000.

How I determine my bid price is I run it through my calculator I built that analyzes 10 different options / scenarios and I bid on it based on a specified return I am targeting based on the worst case option.

How far is it worth going to get competitive bids for the items the pest company should take on?

I have had trouble with accurately estimating rehab costs I'm not sure if the best route is to start calling subcontractors and ask for bids on an example house or if I should just get a GC or someone who is experienced in the area to walk properties with me at the start?