It will always be an expensive hobby. Once you cross that threshold, it can be a lot of fun though!
Just a hint, but make sure that the prices quoted include everything. Generally, a school will quote you a price for the flying part while you will also need to obtain a medical, buy books, may have to take a theoretical course, RT license etcetera. In the Netherlands where I'm based, you need to factor in that every landing during training will set you back a couple of quid too. I usually reckon that you won't get much change back from 10.000 euros to obtain a PPL (based on the Dutch situation). If you manage to do it cheaper, then that's a bonus.
As for the yearly flying, it differs between people as to how much is necessary to stay current. The bare minimum is what's legally required: 12 hours in the 12 months before the expiry date of your rating. If you can manage 24 hours each year, I'd say you're well on the plus side there. On the other hand, I would suggest doing as many hours as you can afford within the first year after obtaining the license as that will help you with the transition to flying completely by yourself. Once you get to 100-150 hours experience* you should have most of the basics down to a point where flying will be as comfortable a routine as driving a car.
* That's just a guesstimate on my part. Opinions on this differ wildly.