my suggestion. try it yourself!
If you look hard enough, theres very well priced shells that people have bought new and don't want anymore, and are forced to sell for much lower than a new shell cost.
like people are saying, all most custom companies have on you is the drilling, and the finish. It's not hard to order parts (especially in the US, damn you guys) and assemble a drum with a pre-made shell.
It's also not too hard to add a finish or a wrap that looks great, with so many guides and options on the internet - just practice on something else first if your staining.
as for bearing edges and drilling.. depending where you are there is usually SOMEONE around who offers that service for no more than a custom company would tack on to your bill.
If you have the same shells (or something better you wouldn't normally be able to afford), lugs and hardware, bearing edges, and wrap or stain as the big guys, why wouldn't its sound as nice? you can save an unholy amount of money, and feel much, much more satisfied.
my example (which I'm going to jinx now)... I found a 4-piece shell pack WITH bearing edges, WITHOUT drilling (Im feeling offset) of solid steam-bent flame birch for $500 canadian. these go for $1500 american new, and this pack is still in box apparently.
who knows if I'll get it for sure, but it just goes to show ya. this isn't once in a lifetime either. I see nice keller shells selling at massive discounts all the time.
just my two cents