I got a classic steel road bike, gazelle tour de France, and one of the fork blades was bent in the frame direction, some two centimetres, after a crash. I read here that this can be realigned, I'd like to know if this is something that can be done at most bike shops and what price should I expect to pay. Thanks.
If the problem occurred in a crash and the wheel was still in the dropouts as opposed to something hitting the bike while it was in a garage with no wheel on, then almost certainly there was a problem with both sides of the fork. Most likely there are issues of misalignment not only in the front to back axis but there will most likely be some twisting involved as well. By that I mean the dropouts are no longer in line with the crown of the fork. Remember that the axel locks the two dropouts together so in a crash both legs wold suffer damage. My guess is the one leg that you described as being bent back towards the frame was on the inside of the wheel during the crash and the other leg was on the side of the impact but instead of being pushed back, it twisted. Long story short is if you are dead set on having this fork repaired, then take it to someone experienced in frame building and not just your local shop. It needs both legs properly looked at. If they can cold work it (meaning no torch needed to heat the metal), then you could possibly get by with a two hour labor charge. But if they have to use the torch to move it out of it's lug or just to make the steel more pliable then you will have to consider the cost of paint as well as the cost of straightening the fork.
2cm seems like a lot to attempt to fix this way. I would not trust this repair to just any old bike shop, but find one that specializes in working on older steel bikes. I'd expect to pay for about an hour of labor at whatever is the going rate for the shop.
I have attempted to do this kind of repair on a fork myself following Sheldon's directions and it's not that easy. Even a relatively minor alignment tweak is difficult to get correct.
The other alternative is to contact a local frame builder and see if the fork can be rebrazed with the correct alignment, or manipulated in some other fashion. Every hand built bike requires this kind of tweaking, so the builder will at least have a lot of practice. I would only go this route if the bike is especially unique in some way. It will require repainting the fork and likely cost a lot more than just finding another similar fork on Ebay.