A week os so ago I priced out hardware and it was over $100 just in corners casters handles and speaker grilles. Add speakers and the wood and it gets expensive fast.
The point is well taken that if you try to engage in a price war with Guitar Center, you will lose. And I suspect it gets worse for bigger cabs with multiple drivers, because of the way that gear is priced.
But building a speaker can be justified under a number of conditions. For instance, an adequate speaker might not be available on the market. I wanted a compact, lightweight speaker with specs that I can believe. Those conditions pretty much committed me to DIY. Also, I just don't need a super heavy duty speaker, so I dispensed with casters, corners, feet, jack plate, and a fancy grill. And I used scrap plywood. My parts cost came in well under 200 bucks for a 1x12 weighing 17 pounds.
One might build a speaker for the joy of doing it. A couple drivers and some plywood are relatively cheap entertainment.
For me, it was also a learning experience. I am a "learn by doing" type of person, and I am practically obsessed with understanding how gear works.
To the OP, I would only question one thing, which is why you want a 6x10. A bit of research on what a 6x10 can do for you in functional terms might lead you to conclude that some other combination of drivers gets you the same or better performance for less cost. In my view, the latest 12" and 15" neo drivers from eminence are game-changing in terms of what a DIY'er can do relative to commercial speakers. I think Bill F commented that if you can't get enough sound from a single 3015LF driver, then you're playing too loud.
