I'm a military guy, prepping now for a SkyWest interview this week. They use a Frasca 142 for their interview.

Couple of lessons learned:
The Frasca is extremely unstable in pitch, so your scan has to be FAST, and you can't spend a lot of time looking at approach plates. I would actually say that it has been money well spent doing the sim prep. The company I am using knows the different airlines' sim profiles, and they can really get you prepped. What you are buying is CONFIDENCE, and that will significantly reduce the stress you feel going into it.
Second, I would strongly recommend Emerald Coast Interview Prep. That course is worth it's weight in gold. Don't think about it, sign up and do it, you're welcome. Trust me on this one.

Good luck!