Tool auctions are a great place to get deals on tools ... BUT you need to know what you are looking at. You can also buy yourself a peck of to trouble and expense by purchasing faulty tools and not knowing how to test or check them before you buy them ... but, having said that, there are still bargins galore at tool auctions.
At woodworkweb we were recently granted permission to video tape both the tools during viewing time and some of the bidding during a large tool auction. We found that anyone who could use the industrial power tools that were going on the auction block, were getting some great deals. The more obscure the power tool, the better the price. Power tools such as jointers and table saws tend to hold their value a bit better because they are so widely used. Something like a horizontal belt sander or even a mid-sized stroke sander, neither of which are in tremendouse demand, tend get pricing numbers a bit lower.
If you are looking for tools and you are satisfied with used tools that might need sharpening, adjusting or even some minor repairs, tool auctions are the place for you, so sit back and see what kinds of tools and machinery you might find at a typical tool auction ....