Not Ebay, but todocollecion. At least, the selleris honest enough to show the reverse. This seller looks at things from the sunny side:
'Some defects
slight oxidation marks on the stamps.'
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The set is catalogued (Edifil CA-14/19) at € 253 unmounted mint, € 170 unused, and € 73.50 used. This seller thinks € 80 is a fair asking price. The price is in the range of what, normally, is asked for a good quality unmounted set.
The large stamp with the terrible oxidation marks accounts for over a third of the catalogue price of the full set in all conditions. The stamp top left with lighter oxidation marks at the bottom accounts for about a quarter of the catalogue price.