Formula - Most Recent Date

My suggestion would be to create a 'Master' table that you can essentially make act as a parent to all of your records. The setup looks like: 

Create new table called Master, no fields needed

Create a single record in that table to create Record ID# 1

Create a relationship between your Master table and prices with Master as the parent table, and allowing QB to make the 'Related Master' field in your prices table. In that field - change the type to formula-numeric and set the value in that formula to the value of 1. No logic, just the number 1. 

What this does is ensure that EVERY record in your prices table gets auto related to that single Master record. 

In that relationship you can then summarize the max import date or whatever date you're targeting. You can then do a reverse lookup back down to prices, and then filter your report where Price Date = Max Date (looked up from your Master table)