We assume the tower would sell for less money because it does not include an LCD. Also we assume the tower would have an upgradeable video card and have slots for more RAM. It could also hold more internal disk drives so as not to cluter the workspace with little boxes and cables and wall worts power supplies.
Two problems with the iMac is that when the computer needs to be replaced you have to toss out a nice LCD monitor with it. and there is no "video in" plug on the iMac, so you might need another LCD.
Ten years ago Apple was able to sell what was then a high end Power Mac inside a tower case for $1,500.
I have heard this for years, but it still makes little sense to me that Apple would make a mini-tower.
This price/performance slot is filled by the iMac right now.
IMO, it's similar to the idea that because the iMac is made with laptop spec parts it's somehow inferior when in fact the opposite is true. The difference between "laptop parts" and "regular parts" is that the laptop parts consume less power are more efficient, lighter weight, and better quality most of the time. They are also often somewhat cheaper.
If Apple made a mini-tower with basic desktop specs, it would compete with the low-end to medium iMacs, yet be more expensive and have not as good quality parts. If they made a good mini-tower it would compete with the high end iMac and the Mac Pro. None of this makes much sense to me.
The only possibility I can see is a low-end mini tower to replace the Mini itself; a sort of ultra-low-budget Mac. But then why would they do that? And on top of everything, this assumes that Apple is ready and willing to write drivers for every low-budget crap video card on the market.
The reason that they don't make a mini-tower is because no one in their market really wants one. They might like a slightly cheaper Mac Pro, but no one really wants a budget crap mini-tower that they can switch the parts around on like with Windows. Unless you are a teenager or a geek, you don't generally upgrade a Mac. I have worked in an all Mac environment for many years now and 95% or more of all the upgrade requests I have seen are for a simple memory upgrade.
Most of our staff just use the computer we plunk down in front of them for three years or so and then get a new one.
It's the "Apple way."
