I have not actually flown with a full-sized bike, but whenever I look into it, it doesn't seem like it's really getting worse, just not any better. Prices are going up, but prices on everything go up. I'm not seeing a huge jump.
One area where I have seen actual improvement: Even just a few years ago, I heard of people having to misrepresent their folding bike just to get it checked as regular luggage and avoid the bicycle fees. It seemed that airlines didn't care that it wasn't oversized luggage, and would charge the full bicycle transport fee no matter what. When I flew last month, both airlines I used had amended their policy to state that any bike that fit into a standard sized suitcase and was under the weight limit was not subject to additional fees.
Of course they trashed my suitcase, because that's what happens when your luggage dates back to a time when they didn't toss the bags around like they were training for the Olympics, but at least they didn't charge me extra for the privilege of having my bag ruined.