We wanted to buy 2 houses and I did a lot of research re auctions, attended a couple, watched Homes u. t. Hammer (even been filmed bidding for the autumn series). We viewed some houses but they reached unrealistically high prices.
Take your renovation costs (most need some work - a few are wrecks) subtract from the expected market price after work and this gives you your ceiling for bids. Factor in a bit of profit unless its your home and a long term investment. What some pay for a fixer upper they can get one ready to move into down the road.
Whilst up for the auction we viewed a few houses with agents. I secured one for a bargain price because we had cash and a fast survey. It needs work but similar houses actually fetch more at auction. We went on to purchase our second with an agent too.
Conclusion - do masses of research, know your prices and reno costs for the area you want. I prepared well and was confident I knew what I was getting into. We didn't get a survey on any auction properties - which would have left me around a grand out of pocket on the three I seriously wanted- but it is a mix of knowing what you are looking at and taking a chance.
There are many publications, websites etc requiring subscriptions, some offering good value others not. Choose your area first. Some auctioneers charge for their catalogues but as we focused on the East Midlands we were delighted to find Graham Penny offered great catalogues free.
I am pleased with our purchases but when our investment one is eventually sold I will return again to the auctions to see if I get my next bargain there. Good luck!