state in the ebay listing that any import or customs clearance responsibilities inlcuding any tax or fines are the responsibility of the purchaser.
already did that
You don't need to do that. Import duties, as the name implies, are duties for the importer, not the exporter. Seller just have to make a declaration of contents and value. Value, not price. Import duties are based on the value of the good imported, not the price you pay for it. You are subject to import duties even if what you get is a gift.
I have been charged duties in a couple of occasions. One of them was when the seller insured the contents. An insured parcel is shouting out loud about expensive material. Custom officers can't stop every single parcel, so they focuse on the big fish.
The other one was a box with carbs, where the seller didn't fill the CN22 form -can't understand how the post clerk allowed the box through-. Custom office sent me a letter to declare content and value, or resign posession. I went there with a printout of the eBay bill. I was told that in Spain, everything above 50 euro including postage is subject to taxes. It was but I was "forgiven", but had to pay a couple of euros for the procedure fees. Needless to say, the trip, gas and time easily exceeded the price of those crappy carbs.
Another time I received a handlebar in a box, closed with duct tape with the customs office logo. The box was from a car rack, and the box was just new. My guess was that somebody at the office didn't believe that the content declaration was true, and opened the box for inspection, just to find out the declaration was true. No custom duties either.
But I know that parcels from China are stopped and charged very often. China is selling cheap electronics, and the UE is very interested in avoiding the tax circumvent.