Essentially, Gary, you are correct. By and large, the preamplifiers used for most commercial releases of any consequence are quite likely to run $1000+ per channel. If you built an 18 track standalone recorder to do commercial work, the 18 channel AD convertor alone would amount to $7000! Then add an 18 channel Neve console with 2-4 "gold channels" at $1500 or so per channel, a dual hard drive with a 4mb processor, $2000 or so, a built in distressor and
a TC Electronics M5000 for FX, and a few thousand bucks worth of plug ins, and you have just built the world's first $35,000 standalone!
On the other hand, your needs are far simpler, because you are layering tracks, not doing a live studio recording, and your signals are mostly beginning in the digital domain. I needed at least 6 simultaneous tracks in (drums), and virtually all of my tracks began as real sound in real acoustic space, which required about $7,500 worth of microphones, and $6,000 worth of preamps.
You can get your signals to the hard drive of a standalone pretty easily, and if you choose wisely, you can export those tracks as WAV files, and not have to go through what I went through. What I think you can't do (well), is the post-production processing of those tracks. The available compression, EQ, and ambience in any standalone is simply not commercial level quality, and that generally is true of computer plug-ins as well. Proper mixing and mastering requires a boat load of expensive outboard gear. The processing of my album "Reunion" used outboard FX and EQ units that individually exceed the cost of any standalone ever made, and with good cause. But like I said- if the music kicks ass, it won't matter. And- if the writing and the playing and the basic engineering sucks, all those high priced boxes with blinking lights won't do diddly to change that. To sum up my position, I think you can track commercial quality music on a standalone, or a PC, if the mics, preamps, and AD conversion are top notch and outboard, but doing the post production work on a standalone will result in a product that can only be so good.
Computers make editing much easier, but the best mixing and mastering virtually always involves dedicated, expensive, outboard hardware, not plugins.-Richie