What's up with Piega P-10 prices?

Under the Audiogon Blue Book, the new price in '98 is listed as $4997. Since several used P-10 pairs have been listed on Audiogon recently with the new price quoted from $10k to 12K+, I wonder where the discrepancy is occurring? I checked the Blue Book on the new price listed for P-8, and these are priced in the threes, new, so the BB prices listed seem to be consistent.
Can the Swiss franc have been so devalued???
Devaluation of the Swiss Franc would not explain this. The opposite would: if the Swiss Franc had strengthened greatly, then $10K might buy required to buy the same product that $5K did four years ago. Alas, this is not exactly what happened over the last few years. Try, for example, http://www.ozforex.com.au/charts.asp to get a five years chart of USD/CHF.
Neither did Switzerland have any relevant inflation over the last several years. Cause for these price increases must lie elsewhere.

PS: My mother bought an early Piega back in 1988 and she still uses them today. At least they seem to last. To keep the trade balances intact, I bought Avalons last summer.
The price in the bluebook is completely wrong.The speaker is very consistant world wide and has never been less than 10,000.00 us dollars. Lookup Lew Lenise review from 99 in stereo times.
I wonder if their were any upgrades made to increase the price. They are excellent speakers and at $5000 it would be a bargain compared to other speakers.
The retail for a pair was close to $10,000 US so perhaps the retail price listed is for one speaker. Or maybe the price listed is just wrong, it wouldn't be the only mistake in there or any such compilation.
I think the issue lies in the way the prices were quoted and would concurr with Herman. In fact I'm quite certain. When I first looked at the speakers I ended up with the 2000 Swiss retail price list and the prices were all for 1 speaker. By the way in 2000 the price in Switzerland was 5940 francs for the plain (non piano finish) version - one speaker. I really don't think there has been any large increase.
the meantime, the P-10s I was lookin' at were bought. Oh well, better safe...