There are many, many wholesale auto auctions across the country. The quality of the vehicles sold at the different auctions probably is pretty similar. It is not so much that one brand of auction is better or worse than any other. Instead; the problem with auction vehicles is that it is not possible to thoroughly evaluate a car's condition without test driving and inspecting it mechanically. The cars that end up being sold at auctions get there for a variety of reasons; but it is usually because they have been repossessed, recovered after being stolen, unloaded by insurance companies; or dumped there by dealers who couldn't sell the car. In other words; auction vehicles are MUCH more likely to have been abused, neglected, or to have undisclosed mechanical problems than the cars you encounter anywhere else. And many of these problams will not be visible; especially to an untrained person. If you find a nice looking, late model Mercedes there, for example; it may be tempting to put in a high bid and buy it on the spot. But what will you do if it turns out that the automatic transmission is shot; because some jerk ran it without any fluid in it? Do you have any idea how much it costs to replace the automatic transmission in a high end Mercedes??? It would easily cost far more than the few thousand dollars you would save on the initial purchase cost.
This is why an untrained person should NEVER buy a car from an auction without fulfilling at least two basic prerequisites: One is being totally willing to accept the possibility that the purchase money you spend might end up being just the tip of a massive iceberg of necessary repair costs. If you need the overall cost of an auction car to not exceed a strict budget; you have no business buying a car there. This is a place for speculators who can afford to take risks; not for people who are already living beyond their means, and who are dreaming of saving a few bucks.
The second absolute requirement (in my book) for buying a car at an auction is to bring a fully QUALIFIED, EXPERIENCED MECHANIC with you; who preferably has successfully evaluated cars at auctions before. Since some things cannot be tested; the mechanic must know what the risks are on a given vehicle, and be willing to rule out those cars which are potential bad deals because of the reputation of that brand; or the likely kind of abuse a car has suffered. And the money it will cost you to contract with such a mechanic will be ultimately worth far more than the amount you pay them. Here again; if you are unhappy with having to pay a mechanic to save you from a potential disaster; you don't belong at an auction.