That is very odd. Sales VAT shouldn't apply as you're buying from outside the EU; import VAT might apply, but as you say, the courier company usually handles the payment of that, and charges it on. I haven't bought art from Ebay for a few years, but that does all sound quite strange. There may be two different issues (Ebay charging VAT and the parcel entering France) depending on how the original owner shipped it - if they didn't put the right customs paperwork on the parcel, with the right HTS code etc. then maybe the French customs refused to accept it? All quite aggravating, I'd imagine!