That’s my view as well, purely as a buyer. 

Simple and elegant design can give an overall impression to attract the buyer, just as clumsy and messy design can do the opposite… but the amount of personalisation needed (or wanted by the seller) on eBay listings to get good and consistent sales is probably best kept to the minimum.

eBay can tinker and in an instant a 3rd party design can go kefupfelupfel. (My own word.)