I think AC fuse is under the hood but don't quote me on it.
If it is seized then it might need to be replaced and depending on what and how will determine price. I do as much of my own work as possible and that has saved me thousands. To change the compressor wouldn't be too hard: purge the AC, disconnect hard lines, electrical wiring, remove accessory (sp?) belt, remove compressor, re-install. I am not too sure but I assume you could check if it is seized by seeing if you can turn the pulley, might have to have the front wheels off the ground, might not, anybody else have input on that. This is something I haven't had to work on yet.