Equipment:
Tank: $400 (for a good used tank, can be upwards of $800 new)
Vapor Shipper: $800 (if you plan to be transporting your own, this canister can be mailed)
AI Kit: $140 (give or take for a new kit, includes gun, speculum, sheaths, thaw jar, light, etc)
Stand: $200 (if you don't already milk on a stand)
Semen: 5/$125 (is about the average price of semen + shipping/vapor rental~if you don't have your own~)
Nitrogen: $40+/- every three month for a fill
Helper w/ experience: priceless
Sounds expensive, but when you figure the purchase cost of the bucks themselves (in some cases upwards of $2,000), feed and labor costs for his upkeep, and the fact that you can only use 1 buck so many times (if you like and keep his daughters), AI can be a reasonable thing to get into.
I have the tank, I've been slowly acquiring semen. This fall will I will be attempting the actual AI process. I have a friend that has tried several times and hasn't gotten it right yet. But I also know of quite a few herds that have great success with it. It's one of those things that's a pain in the ### until you get it right, then it seems to get a lot easier.