Tbf, some sellers via auction are just looking for a transaction that they know will go through without hitch once the hammer falls. In my (limited) experience that often means sellers that are organisations rather than individuals, because the throughput of cashflow is more important than squeezing every last ten thousand out of the buyer, which is why you might be able to get a bargain.
For example, I was wanting to buy a cottage being sold by a railway authority, which was one of a Victorian terrace that had been built to house railway workers. I know the area well and had been in other houses in the terrace, and knew they were really solidly built and that there were no damp or subsidence issues, for example. I viewed it with a friend who had recently done their own refurb so I could get a sense of costs. I'd also gone through the legal pack with a fine-tooth comb, and I knew the ceiling price on the road. The guide price was very attractive (£115K), the ceiling price once done to a good standard about £265K. It probably needed £40-50K spending on it. Unfortunately, lots of other people had made the same calculations and it went for about £230 iirc - so about double the guide price and almost exactly what the numbers suggested was the upper limit. It was bought by a developer, slurped up, and is now tenanted (grrr). So you can get a decent house that's not a money pit, but you have to do your homework, and even then you may not get it on the day.
But pp are right, a lot of auction houses are shitholes, and while you may think it's just about cleaning them up and applying some tlc, the fact is that houses that get into that state are often harbouring large, expensive problems and/or need expensive reconfiguration after being HMOs, for example.
If you are buying an unmortgageable property, you need to consider whether it will ever be mortgageable, as that would affect your resale prospects. Lack of a kitchen is reversible, documented subsidence or dorran prefabs not so much.