@Chris Berg the loan position information in PropertyRadar is based on computer models, and while it is a great starting point it should not be relied on for purchasing at auction, as per the disclaimer in the software. Also, the transaction history in PropertyRadar only includes voluntary liens and transfers - it does not include involuntary liens (mechanics liens, tax liens, judgements), so you will still need to research those regardless.
As @David Mitchell said, the best answer is to educate yourself on the title search process, and then you can easily verify the loan positions in PropertyRadar and check for involuntary liens using your local county recorder (often online).
Note that even if you pay the title company $150-250 for a title search, those searches do not come with a guarantees and the title companies themselves do make mistakes - thus the reason for title insurance. I'm not trying to scare you off doing trustee sales, just want to be clear that getting a title search from a title company doesn't guarantee it to be accurate - unless it is backed by an insurance policy.
That said, and depending on your planned volume, we do have title companies that will provide free title searches in exchange for your title business. Feel free to PM for contact info. I would say this is what the majority of our customers do, followed by a group that has educated themselves and do their own, followed by a few folks who truly do just wing it. I personally bought 150+ properties at auction doing my own title work and only had a couple that came back to bite me.