I've bought stuff from all over the place.
Ebay - T\S, Extractor, Router, Bandsaw, etc.
Shows - unfortunately being up North, doesn't mean much for shows, except the North of England Woodworking show - so, my nice to haves\treats wait for that. If you are after several things - the vendors will haggle. Last time paid 250 for Metabo's 150mm ROS and one of their Jigsaws, saving at least £40 on the pair.
Even got the Festool bug - so have the readies sat for a TS55 and guides, and loads of systainers.
Freeads - bought a well looked after large Lorum P\T for penauts, as the chap was upgrading.
The only thing is that unless it's new and from a reputable mail order outfit - it's always cash on collection on high value items or those where there are fakes.
Ultimately depends what your after - new or old or like me, aren't hugely fussed (obviously depending on price\condition).
But I've always bought well ahead of time - even if I won't be using it for upto a year. That way, price\condition are the ultimate considerations and it won't be because I couldn't stop salivating.