auction-style postings for variable products

I’m afraid that’s not possible – only fixed price listings can have variations on eBay.

This is not a limitation of WP-Lister but of eBay itself. I tried to find something in eBay’s online help as a reference, but this doesn’t seem to be part of their FAQ. The fact that they refer to variable listings as “multi-variation Fixed Price listings” in their documentation kind of gives it away though:

https://pages.ebay.com/sellerinformation/build-your-business-online/boost-profits/multiple-variations.html

kind regards,

Matt