Ok, Apple Computer makes great products that are plug and play. Provided that everything is all the same age. For example, if you have one of the first generation Apple-branded flat screen monitors, you cannot plug it into a Mac mini. The pin assignment and whatnot of the plug have not changed. But the size of the plug has changed. The Apple stores don't sell adaptors.
Maybe Apple resellers sell an adaptor, but that's hard to know since apple intentionally bankrupted most of them. It's worth noting here, as an aside, that the VGA plug has not changed since it was introduced. While your 1999 Apple monitor is "too old," you 1985 VGA monitor will still work fine with any VGA-equipped computer.
It's time to stop pretending that Apple is somehow the high road. They do every Microsoft-like trick they can get away with. The only reason their products are better is because they're trying to catch up in market share. If they achieved the position of dominance that Microsoft has, they would start selling crap products too.
For desktop computers, I'm switching to linux from now on. I have to build half the tools that I use anyway. It would only be slightly more work to build the whole system and at least then I would have the latest version of everything instead of waiting for the fink port.
Ok, the reason the plug changed is because Apple decided to switch from their own standard to an industry standard, which is an idea that I support. However, it's still true that their own stores don't carry the $100 adaptors and that all the best resellers are dead. And that their so-called geniuses don't tell you jack about what's up with changing plug sizes. Also, if you want to add RAM to a Mac mini, you're going to be shelling out for an hour of labor. Ouch. Order it with the ram, don't plan to upgrade.