How to provide price comparision of commercial products
I have cited prices in academia.  Is very relevant in energy, etc.  I was OK with approximate prices because I was comparing items with orders of magnitude different price, so figuring exact prices, discounts, was not critical to the report.  The info was not public, so I had to run a couple customer interviews to get it.

You could also consider to just buy a copy of each (if reasonable) and charge to the grant.  Also allows you to do testing, etc.  One other option is to just have some app do website scraping for the prices.  There are services that do this or you could just write your own.