The only way to verify sales concessions is to call the listing agent and ask them to disclose it. Unfortunatly, it is not required that the agent disclose this in MLS (it really should be).
It’s easy to spot them with a single listing price as the sales price will typically be exactly $5k or $10k over list. With market times of 45-90 days its unlikely anyone put a true offer in over list.
With the variable range, there is no way to tell w/o calling. I have no doubt many of the sales in the variable range sample had concessions as well, but the majority had final sales prices significantly higher than the low end price (more than 5-10k).
Why would someone offer a price higher than the low end? Maybe they didn’t, got countered, let emotion take over and accepted the higher counter offer.
In any case, variable range listing is a good way to maximize the final sales price and it appears to still be working for many sellers even in this softer market.