Like Google, the eBay noise-to-signal ratio is abysmal and getting worse. With Google it's planned that way but it's hard to see any net benefit on eBay.
Depending on the kind/size of lathe you are looking for, limiting the search to Business & Industrial might miss a few – particularly small lathes.
In the left pane, you might want to limit on 'Distance' for an item of this type (you aren't very likely to want to ship around the globe).
In principle, you should be able to limit on minimum price – you're not going to get much of a lathe for £2.98 – but the practice among some of setting a very low starting price (£0.01) together with a much higher reserve may preclude that. eBay should really limit this. (This works better for "Buy-It-Now" items).
Don't forget exclusionary ( "-" ) search terms to sift through some of the noise. This can be very useful. Thus you might want to search:
lathe -bit -carbide -pen -watchmakers ….. (etc)
You can keep adding exclusion terms and re-searching as you go along and it becomes apparent where the main noise is.
Edited By Sid Herbage on 10/08/2012 00:57:15