Price comparison website
While I don't have the detailed steps, I suggest you look to the Views module. The relationships and/or contextual filters provide WHERE and FROM type SQL queries. 

If you have two views, one based on each vocabulary (taxonomy lists), and each has a contextual filter (with block settings to show only on specific page) then you will get a correlated listing on page/block sets. 

If you have troubles getting it going, try exposed filters and AJAX refresh options - Get close enough to help your users help themselves. From a marketing angle, even if automatic/ideal results aren't automatic yet, IF views exposed filters get your customers/staff/partners to answers within 60 seconds from only a click or two, AND they also see message/indication you are actively working on the automatic results, the anticipated "better" site will up their anticipation and your reputation with most people (if, of course, presented with care).

Alternate possible "maybe" modules are "Views Field View" or "EVA". The "Better Exposed Filters" module might also be handy.

Try a search inurl:tutorial-6-10-views-relationships-and-contextual-filter for a great video. 

Good luck.