There is a lot of variation in the selling price on these units on GL, I tend to only track the selling prices of the smaller units up to the MEP-003a 10KW generators. There are some general rules of thumb, trailer mounted units and ones with ASK housing will tend to go for more than bare skid mounted units. There are a lot of non-merit based auction dynamics at play, sometimes deals can be found when large numbers of generators are listed, other times it seems like there are one or two big buyers that are willing to bid up the prices to so they can get all of the units at a site, perhaps to make it worth it to them to send a dedicated truck for pickup. Often due to GL's 15 minute rule the best deals can be found on the middle of the pack less than great looking generators, what tends to happen when there are a group of lets say 10-15 mostly identical sets with 2-3 nicer looking ones (low hours showing, good condition, accessory parts visible, etc.) and also 2 -3 rougher than average units (high hours showing, mix and match colors, dents, dings, etc.). First the prices get driven up on the prime looking generators, then the people on a budget start bidding on those mid dle of the pack less prime looking ones, but skip over the bottom "rejects" Then a strange thing happens as closing time approaches, at say 10 minutes until closing people will start bidding up the price on those "rejects" and some of the middle of the pack generators. This becomes a 15 minute rule violation, pushing the closing time back until after the scheduled time, the nicer units and some of the middle of the pack units sell at the expected closing time, this leaves everyone else left going into a bidding frenzy on what is left, at this point the prices may still be less than the nice ones sold far, but each bid starts that 15 minute countdown again, so as a result you end up with the less choice units ending up selling in a bidding frenzy 30-45 minutes after scheduled closing time at a price significantly higher than the sell price of those "nicer" units that closed on schedule. I have seen this cause bare but functional looking MEP-003a's that typically sell in the $1,100 - $1,600 range go for $4,000+, which I consider insane on an as-is GL auction. Location, time of year, and recent storm events tend to also effect prices, but when it comes down to it some days prices just seem to go higher than others, some days it is insanely higher, if you don't have to then don't get caught up in the frenzy, and wait and bid again next time around. A couple of months ago I watched this happen to a GL auction near here to a degree that makes no sense at all to me with MEP-002a's selling at prices well above what you could buy them for from the various resellers ($1,800 - $4,100 for skid mounted 5KW MEP-002a's back in Oct, these were nothing special showing several hundred hours on the meters, not fresh resets or anything, but comparison I bought my MEP-002a about 18 months ago for $400, which is a bit low, typically around here they have been selling in $500- $800 range most times).
