That's basically it.
The wood type and construction doesn't change so much as people want to make you believe, but don't underestimate the importance of hardware. A good drumset stands or falls - literally - by the hardware quality, especially as hardware deteriorates over time and cannot be replaced like skins can. Another factor are the shells dimensions - which are rather limited for entry level - which contribute more to the overall sound than the wood type.
You're not only paying for the sound but also for durability, options and looks.
This is true. I've been on a big Keller kick here lately as anyone who's read my recent posts can attest. Here's the thing: most people recognize that going with a ply shell and using 100% maple is completely pro. Sure you could quibble with where did the maple come from and was it DW, Yamaha, Sonor, or was it Pacific, OCDP, or Ddrum? Maybe valid questions, or maybe not so much. Depends. If you got a crappy Ddrum (for example), any problems with the shell are most likely related to how well they wrapped it and cut the bearing edges. You can kill the sound by botching either of those.
Buy yourself a set of Keller shells in whatever diameters and depths (no limits here at all) that suit your tastes, pick out your drum hardware (lugs, spurs, etc) get 2.3 mm hoops, and then do two more things: 1) finish them in an attractive stain and oil: plastic lacquers (polyurethane) and drum wraps will dampen the shell to some degree, and 2) make sure the bearing edges are cut evenly and sharp by someone who knows what they're doing.
I expect to be taken to task regarding finishes here, but I think that if your going to all the trouble to use low-mass hardware, non-grounding suspension systems and everything else, why would you then essentially laminate your shell with plastic that could only serve to dampen the shell? To me it just seems you've defeated all that effort to promote maximum shell resonance. It's like a virtual piece of duct tape permanently affixed to any head you put on your drum.
After that, buy good hardware. It doesn't need to be DW 9000 because again, you don't need to break the bank or your back. But as Thunderstix pointed out, it needs to do the job without question or trouble.
And that's it. You'll have spent far less than you would have if you'd gone Sonor, Gretsch USA, DW or Truth, and soundwise, you'll be able to put your kit up against any of theirs because you've got a shell and a bearing edge of comparable quality. The rest is in your head selection and tuning abilities, which are easily learned.
I've been playing Keller-based kits that were relatively inexpensive for the last 15 years and have yet to find a kit that I thought fundamentally sounded better. I know how to tune pretty well and don't totally suck at playing and my kit sounds great.
Don't get too wrapped up in brand names and price points. Try and pay more attention to the workmanship and above all else, remember to always keep the most important thing the most important thing: the sound.
BTW: my kit looks like hell. It's a "working kit" for sure, kinda like one of Clapton's old guitars. Much of what you pay for at the very high end are the latest hardware features, and a pristine finish that you'd be too freaked out about taking on a gig anywhere. Think about that...