XF is listed at around £135.00
UNC is listed at nearly £700.00
I was shocked at these listing
I'm not surprised at all. I got interested in collecting the Euro after a 2005 visit to Ireland. The design didn't do anything for me but I found the odd Duisenberg note in really rough/ratty shape (everything was Trichet by that time). So when I got back to Canada, I actively sought any Duisenberg Euro (5-20) I could buy at a decent price. However, I rarely saw UNC Duisenberg offered (mostly Trichet & Draghi or circulated) so just trying to get a few UNC examples became a real challenge. I followed the EuroBillTracker site but lost interest in trying to get notes from any of the tougher nations (tougher prefixes).
By the time the first signature variations were being offered, they were listed in a "king's ransom" (IMO: way too dear) so it became a bit of a turn off & I just abandoned the early Euro pursuit. The more reasonable priced Duisenberg Euros were printed in Germany (X), France (U), Italy (S) or Netherlands (P) (for 5-20 Euros). I even found “Trichet” versions to be pricey considering their lengthy release & started to look for pre-Euro (which had much nicer designs).