I assume you mean 30% off for a used bike that is last year's model? Not last year's bikes new for 1/3 off.
Nope! Last year's new bikes from bike shops are regularly discounted 30% off to get them out of the store. Just got myself a trek FX 7.5 2012 for $800 brand new at the shop. The FX 7.5 2013 is $1100 :)
Have you seen 30% off as prices go up? A few years ago, I bought a Trek Madone 5.2 at the local shop for $3099. The prior year's bike was discounted by something like $150-200 and had slightly inferior components due to an improvement in the Ultegra group that year. Those prices were typical of my online comparison shopping for the two model years, and the shop had a no-price-negotiation policy.
Before I get any face punches, I realize it's a crazy amount of money for a bike. It was pre-mustachian and was probably my greatest splurge. I do very much enjoy riding it, though, and can't convince myself it would be worth selling on the used market. I was putting in a couple thousand miles a year, and am trying to get back to that level again since giving myself some facepunches for excess driving.
As an aside, a few years before that, at another shop, I got $100 off my much more practical, but still not cheap, Surly Long-haul Trucker by paying cash (discounted from $1,000 to $900). I was kind of surprised at the cash discount, since I don't think they can keep that off the books very easily... (btw, from a recent Freakonomics podcast: nearly 17% of US income taxes go uncollected due to not being reported - $450 billion per year. The biggest portion of that is unreported cash collections by small businesses).