Ignore what the How-To Geek says, he doesn't know what he's talking about (joke!).
My problem w/ that particular Mac Mini for sale is that the person includes software as a part of the bundle. I doubt very, very much that they're including the actual, legitimate and legal original versions. Even though it comes with Leopard, it's probably his/her installed version - the version of OS X that actually came with that Mac (the disk that's hopefully included in that sale) is likely Tiger (10.4). So if the OS failed and you had to recover (which, btw, hasn't happened to me once in the 3 years and 2 Macs I've been using - and I abuse the hell out of these things) - you'd be recovering to Tiger, and all of that "included software" would be gone.
I'd suggest contacting the seller and asking for a lower price, unless they're going to provide the original discs for all that software (in which case the deal is totally worth it as Adobe Creative Suite 2 alone costs $700).
Before my current MacBook Pro (which is a 1st gen and considered "slow" as far as MacBook Pro's go), I had a PowerBook (G4 based). It had a 1GHz PPC chip, and a gig of RAM. It ran Tiger like a dream. I'm not sure how it would handle Leopard, because I had to give it back to my employer when I quit. I can't really compare a 1.25GHz PPC to an Intel or AMD CPU because I honestly have no idea how they'd compare. I just know that my old G4 PowerBook ran Tiger and all the apps I used (note: that didn't include PhotoShop, which is a pretty big resource pig) very quickly.
The Mac Mini's are, as I'm sure you've heard, a serious pain to upgrade. But, it can be done. There are dozens, probably hundreds, of tutorials online that show you how. A decent video one can be found here: http://eshop.macsales.com/tech.....i/med.html
If you really want a Mac just to experiment with and "learn", I'd suggest a very very cheap G3 running 10.3. There's a lot of software you won't be able to use on the G3, but certainly enough that you'll 1) get an idea if OS X is something you're interested in and 2) you should be able to get one for less than $100. But 10.3 really uhh is NOT as good as 10.4, let along Leopard. I guess it comes down to your personal budget. If you decide OS X isn't for you, less than $100 isn't too bad. If you decide OS X is for you (which you will), you'll start to save up for a brand spanking new MacBook/MacBook Pro/Mac Pro/iMac.
Now just for fun, I'm going to tease the How-To Geek.
1. Hide the dock you baby. The top menu bar takes up less screen real-estate than a single-row Task Bar in 2k/XP/Vista. And I know you have huge monitors, suck it up.
2. Use Safari for full screen.
3. Less annoying than you make it out to be. Just click twice. Girl.
4. You don't need to theme it because it's genuinely gorgeous out of the box. And even if you don't love it, you can theme a lot of it. Icons, scrollbars, the dock you hate, the menu bar you hate etc, are all customizable.
5. Yeah the font thing is annoying if you use non-Carbon apps. So you have to set font size on an app-by-app basis (for non-Carbon ones). Life goes on.
6. It's called Quicksilver. Learn it, live it, love it. And Gnome-Do, Launchy, whatever - none of them come anywhere close to the genius power that is Quicksilver.
7. Really? I didn't know that. That does kinda suck. Stop running Vista on a Mac.
8. That's not a negative. (Again, I'm joking).
9. Use Vistor, by the same group of brilliant basta#*$ that make Quicksilver. It's like Terminal as a Quake console. Oh and it has tabs. And can't you launch it w/ the & command anyway, so you can use that Terminal?
Before the forum regulars call me all sorts of names, I was totally just kidding around w/ HTG. None of my responses to his gripes were meant as anything other than jokes. I like Vista too, honest. Texas Hold 'Em is awesome (the one included in the Vista Ultimate pack).