Dell's profits have been slumping over the last year while Apple continues to break its own revenue and profit records. Apple's margins hover between 30% and 40%, which is one of the ways it stays in business. Comparing specs between machines from different manufacturers, however tempting, does not give you the full story, and is certainly not what the majority of Apple's customers will be doing, as others have already pointed out here.
Nor, really does comparing Dell and Apple's profit margins. Dell don't just sell to consumers, they sell multiple OS platforms on a large scale to enterprise, which is a far more cutthroat business for OEMs than the home consumer market. If someone buys a second computer in a household there is no obligation to buy from any given OEM. Not so in enterprise - large firms who buy bits from Dell, bits from HP, and bits from Lenovo are few and far between because OEM's will tender for a contract for a period of years, often undercutting each other to tender successfully. If Apple's business model revolved around this their profit margins would be nowhere near as big as they are.
Apple's enterprise market share is virtually non existent because their Xserve hardware solution is tied to OS X and there are very few enterprise apps of note for OS X. They purposefully avoid trying to make in roads into the enterprise market to avoid the reasons above. For every Xserve solution there are countless Linux / Solaris / HP-UX / other Unix solutions available, no doubt with better upgradability and more importantly, enterprise support.
Apple makes its money from overpriced computer hardware to the home, education and media niche markets, and consumer products like the iPod / iPhone and iTunes Store; markets which the latter 3 Dell have no business in.
You can be pretty sure that if Apple wasn't selling enough computers at the prices they set for them, they'll either drop the prices or drop the computers (remember the G4 Cube, the multi-coloured iBook, etc.).
Another badly thought out point - all those products had comparable units available at the time to replace them:
Power Mac G4 Cube -> Base model Power Mac G4; cheaper and more upgradable
Multi coloured iBook -> white iBook G3 superceded the coloured iBooks. Again, better technology.
The Mac Mini has had no such comparable model. The options were either an iMac or a Macbook. The G4 Cube is a bad example as it was designed as a Power Mac line; the Mini is firmly stated as a consumer line.
Wikipedia said:
Apple targeted the Cube at the market between the iMac G3 and the Power Macintosh G4. Despite its innovative design, critics complained that it was too expensive. It was initially priced US$2000 higher than the comparably-equipped and more-expandable base Power Mac G4 of the time (450 MHz CPU, 64 MB RAM, 20 GB hard drive) and did not include a monitor, thus leading to slow sales
I would love to see some Mini sales figures over the last 2 or 3 years. As the hardware became more and more outdated and the price points remained more or less the same, the number of sales would have gone down. Why continue manufacturing them? Because the cost of the internals was also going down and therefore by maintaining the price points on the hardware the units that did sell would have a huge profit margin on them.
