Used speaker question (Klipsch)

I found a set of speakers and sub (no receiver) on Facebook for $500. Is it worth getting? Since I don't have a head unit to test them, I was going to bring a DMM and check resistance on each.

The Klipsch HD Reference Series:

2 RF-10 Floor standing speakers

2 RS-10 Surround speakers

1 RC-10 Center Speaker

1 RW-10 Subwoofer

Cables included