When I tell people I'm trying to build guitars, the first thing they ask is how; then they want to know how much it costs. I will tell you this: don't get into building guitars to save money. Over time, yes, I suppose I will but the initial investment has proven substantial and quite frustrating at times. I think that even a well-stocked hobbyist carpenter or even a professional would find himself needing to make a pretty a substantial investment in tools. I'd estimate that I've spent about six hundred dollars in tools so far and that is pretty conservative. Of course, I have bought some things that have proven unnecessary but at the same time not a day of work goes by where I didn't wish I had something else to make the job go by more smoothly. It's very expensive to say the least.
Beyond even the initial costs of buying the tools, there's the expense of the consumable parts. A good router bit will cost you between ten and thirty dollars and you need several of them. Quality sandpaper costs more than you would think and you need lots of that. I've bought at least two drill bits that have cost me over ten dollars thus far and will have to buy more still. Then there's things like dusk masks, tape (I spent fifteen dollars on tape today), paint brushes and the gloves I've been wearing to test out finishes and so forth. Around every corner there's another dollar to spend--and he's hanging out w/ ninety-nine of his good buddies.
Of course, there's the price of the actual material of the guitar. The slab of mahogany only cost me fifty bucks--rather cheap for what it is mind you--but that's not the half of it. Even the cheapest pickups cost thirty-five bucks for the set (and that's bottom end) and high-end ones are going to cost you around seventy to a hundred-fifty and more a piece. You have to buy a couple or four knobs at three to ten bucks a pop. Then there's the wire, output jacks, strap buttons, the bridge, control cavity covers, the screws for the bridge, the screws for the control cavity covers, shielding for the control cavity, the pickup selector and more than I can even think of. These things cost money and it adds up pretty quick. My neck cost me around three hundred on top of that but if you were to make that yourself there'd be the cost of the wood, the nut mater, frets and the tuners--not to mention the additional tools you would need to make it. Again, this stuff is not cheap.
And then the labor! If I made minimum wage for the research and actual build time I put into this, I could feed all of the many starving people0 of French Indochina and have enough money left over to buy a Mexican Fender and a new Champion 600 which I could rock to kingdom come. You think about the time you spend actually doing the work but you don't realize the time you spend doing design, scouring eBay for deals or doing Google searches to figure out if the difference in spacing between a telecaster bridge and a p90 pickup will cause problems. (I would like to thank the fellows at Guitar Fetish for clearing this up for me. It's fine. Don't worry.) This might not be something you want to get into if you have a newborn baby or or one of the girlfriends who's constantly bitching, bitching, bitching that you don't spend enough time w/ her (mine does not, otherwise she could not stand to be around me).
So... W/ all this said you might think I'd want to discourage you from building--and I do, if you are in it to try to get guitars on the cheap. I firmly believe that any clown w/ half an idea of what they want to sound like can go out and find a guitar that's absolutely perfect for them for under five-hundred bucks--and if that's all you want, do that. However, if you love guitars, love doing things w/ you hands and love not relying on someone else's craftsmanship, then go buy some damn wood and get building already!