There are very few power tools I have purchased new. However, the second hand ones I go for are Festool and Elu. I also have a Mirka Ceros sander, also second hand. Purchased carefully, it is possible to get high quality tools for 1/3 of the new price. For example, 15 years ago I purchased a used Festo sander, the forerunner of the Festool 150/3, which was already 10 years old. And it is still going strong. The same can be said for the Elu 177e and MOF 97 and MOF98. I have just sold a Makita 4300BV jigsaw which I purchased 20 years ago. This is built like a tank and in good condition. I replaced it with a Festool Trion for less than a 1/3, in excellent condition. The old Makita lacked dust control, which the Festool has in spades.
One of the great bargains of power tools is this little router which all recognise as the Katsu (it goes under a few names) ...
I have the Makita trim router upon which it is copied (also purchased used), however the copy was so cheap that one can not argue with a new one of these. It works as well as the Makita once the collet was replaced. I do not expect it to last as well, as I doubt that the bearings are in the same class.
Used Elu routers must be the bargain of the century. I purchased a 177e new in 1990 (so it is now 32 years old), and it was not cheap - same price as a the large Festool 2000 router at that time. The Elu just was nicer to use. A few years ago I purchased another on eBay (UK) for very little, and it now powers my router table.
Two cheap great tools for the router table: MuscleChuck (above table bit changing) and Router Raizer (a LOT cheaper than a router lift) ..
Build your own router table and router fence:
http://www.inthewoodshop.com/Powered Tools and Machinery/RouterTableAdventure.html
Yes, another cheap way to get quality tools is to make them yourself!
This 17 tpi dovetail saw with a thin 0.015" plate cost me $39 USD to make ...
I have made many saws, mallets, cutting gauges, hand planes, and the like.
http://www.inthewoodshop.com/ShopMadeTools/index.html
Balanced against these savings are expensive, premium equipment, where I did not skimp. I would happily have purchased these second hand as well, but they rarely come up for sale in my neck of the woods. Fortunately I have a supportive wife.
Regards from Perth
Derek