$630 for a new Austrian 280 did seem a bit much. The buyer must have really wanted the racket to bid it up so high. ( One always wonders how much shill bidding takes place given the anonymous bidding on the bay now. That could have been a driving factor. ) I thought the racket would probably sell in the $300 to $400 range and was somewhat shocked, along with everyone else, to see it go for that much. The fact the seller has no feedback didn't even seem to be a factor. On occasion, bidders act in irrational ways. That auction seems to be an anomaly as evidenced by the other new one which sold this week for around $350. The $630 racket had been strung so one has to question its true virginity. I think the buyer paid too much but that is his prerogative.
A new 280 is very rare and is a collector's item. Collectible rackets will always sell at a substantial premium. $350 for a new, never hit with, never strung 280 with grip wrapper in place doesn't seem out of line given what used ones in mint condition sometimes sell for. Look what people pay for rare baseball cards or Shaker chairs or Van Gogh's. Collectors place much higher valuation on certain items than you or I would.
Someone in Canada sold a couple of new designed ins a couple of months ago. I recall they went for around $280/each as buy it nows. The grip wrapper had been removed but they were unblemished.
An auction like the $630 racket isn't typical. Used 280's can sell anywhere from as low as $50 to as high as $250 depending on condition and origin. The vast majority seem to sell in the $75 to $150 range. The selling price distribution seems pretty much a classic bell curve. The average selling price on the bay seems to be around $100.
Before the 280 became a cult classic, around 2001, I bought two slightly used 280's on the bay from a guy in Torrington, CT for either 29.99 or $39.99 for both! I was the only bidder and they were both 9/10 range. Those days are gone.
Paint job rackets are a different category, also collectible, and usually sell for a much higher price than made for consumer 280's. Someone recently was selling a 280 that had been spray painted black as a paint job racket. I found that rather amusing.
The funniest auction I ever saw on the bay was around 2000 or 2001. A guy was selling a smashed Adidas GTX claiming it had been smashed by Lendl. Of course, absolutely no proof was offered and he was asking about $300 if memory serves.
So, go out and smash a beat up 280 to smithereens and then put it on the bay claiming Muster or Guga was uncharacteristically irritable that day. ;o)