I'm pretty sure the person must've been referring, intentionally or not, to the fact that Apple is apparently only issuing continuing updates (security, mostly) to the current version (or maybe one past) of OSX--10.1 users, so far as I know, aren't getting any security updates, though to be honest I'm not positive they need any, either.
That would indirecly imply you'll have to pay Apple $130 a year for ongoing security fixes, so to speak, even if that's not technically what's going on, which is what mgargan1 said.
And since we're bringing MS into this, how about their charging people $10 a month to use IE version 6 on the Mac? Not much cheaper than Apple's OS upgrades, and you can't keep using whatever you've got if you stop paying for it. To a degree, you could say the same about .Mac, but in any case Apple couldn't switch to a monthly/annual licencing aggreement for existing users, but if you start it that way from the begining....