I just had a Fender Del Mar acoustic guitar repaired here in New York City. I know this question is gonna be hard to answer, since all guitar repairs are different, but here goes:
How much should it cost to reattach an acoustic guitar neck? It wasn’t completely seperated from the body.
A neck reset is a pretty expense repair. Propably looking atleast a couple hundred. I am not an expert and maybe you don’t need a neck reset, but if the neck is seperating form the body I would say you do.
try the message board at acguitar.com
Depending on the reason for the neck displacement it could also be a very cheap repair. If it simply lost the glue and came undone that is a cheap repair. If you smashed it against something and it broke, that is an expensive repair. If it is something akin to the latter then your guitar will never sound as good as it originally did. You would be best off looking to buy another guitar.
For the most part the only work that you should ever do on a guitar that won’t really negatively effect the sound are as follows: putting on new bridge/neck nuts (not the bridge itself), setting up the frets (it involves sanding them down so you won’t get fret buzz), and fiddling with the tuning keys (to help them keep the tune). If the repair is a simple reglue job it could be worth it.
When I was still a professional classical guitarist I would only suggest that you repair an instrument that is luthier made since they tend to be 5-20 times more expensive than a typical manufactured guitar and tend to sound better overall anyway. Since we don’t know the extent of the repairs that you want to do we can not be sure of what to suggest. So you know, extensive body work (ie, the neck is broken and cracked the backboard) could run you more than the cost of the guitar.