Yep, still as crazily priced as when Stewart mentioned it a few posts below ;)

If it's firsthand, then the seller should have at least some idea of what they paid for it in 1976. Looking at the other watches the seller has for sale and some of the past auctions, I think it's probably a typo. I reckon they wanted to put 500,00€ but mistakenly put the numerals after the decimal point (well, decimal comma in this case) ahead of it, inflating it 100 times. 500 Euros would be an entirely sensible start price.