I've literally spend millions in all kind of verticals from finance to travel, from consumers electronics to fashion. If your ROI (or any other target you set like branding, ROPO, etc) is good than Adwords is not too expensive. Of course it would be nice if it was cheaper, butthat's all part of the game you are playing
Bidding costs do appear to have rised, however it is more easier than ever to measure your ROI. This should avoid you wasting money on non-peforming keywords/ads, resulting in better value for money advertising.
It depends on your market niche. I have clients who are paying $50/click and others that are paying $0.25 - totally different markets and both make profits from at those costs.