I contacted ebay to clarify the position on this and this was the response I got:

 

RE: Advanced selling tools SR# 1-105590026719


Hello,

 

I hope you are having a nice day!

 

The store subscription level doesn’t any influence with the placement in the search results. Since the best match results are based on algorithm, there isn’t any concrete reason why a certain listing ranked higher or can be found at the bottom page. We however highlighted several factors that affect the items placement/ranking in the best match page. First are sellers who are offering premium services, top rated sellers, feedback with high percentage score, items with sales history, best priced items with significant views and impressions. It would be best if you focus in participating site  activities that promotes increased exposure and visibility of your products such as the eBay deals.

 

Best regards,

Jean Pa