Quandary

If you're happy with your system now, I'd leave well enough alone.  

As far as paying for the audition, I think everything is negotiable. And I'd rather audition the actual amp rather than it's big brother.

Interesting sales tactic though. What if you really like the 60w monoblocks, would you then buy the 30w amp without hearing it? 

As to the cost of the audition, if $300 is that outrageous in today's market then you should have no trouble finding a Pass dealer to allow you to audition for a lot less. Just remember to factor in delivery, setup, take down and return back to the dealership. 

I would want to audition exactly the amp I was considering buying. No exceptions. And 30 watts and 60 watts might sound very different, that's double the power.

As for paying $300, it might be worth it, this would not be an issue for me.

The Benchmark AHB2 and PASS sounds very different. If your speaker is little bright then the PASS could be better, though I would use a CODA or the KRELL DUO XD over PASS on a slightly bright speaker. I find PASS too warm for my tastes.

I have a slightly warm headphone heading my way soon, the RAAL 1995 Immanis. I have the Schitt Aegir Class A amp, which is similar to the PASS, as my amp for these phones with my tuners. It will not be a great match (just OK), The AHB2 would have been perfect because it can blend into that warmth, unfortunately, I recently sold the AHB2.

BTW - Even though the AHB2 was underpowered for my Yamaha NS5000 speakers with some music. I was able to determine what speaker wires worked the best with my Yamaha NS5000, ONLY with the AHB2. The AHB2 is so revealing that I could hear what each piece of my system was adding positively or negatively. I ended up with the Audience FrontRow speaker cables because those had 0 fatigue or anomalies that I could hear via the AHB2. I now use a CODA #16 amp (and FrontRow) with the NS5000 since it is a better power match. The AHB2 is a great amp.

@rvpiano I’ll going to play devil’s advocate here for a minute…

I want to say that a $300 home audition of an amplifier doesn’t sound that great…on the surface. But consider this - he will bring the amp, set it up, then come pick it up when you’re done with the audition. You don’t have to wrestle a 100lb amplifier into your room, out of the box and into your component rack, then back in the box after you’re done. He charges less than the Cable Company (they charge 5% + tax + shipping…they do apply this amount toward the purchase though). So if he does the same thing, I don’t think it’s ridiculous. 
However, you can pick up this XA30.8 amp used and do all this yourself. Sell it if you don’t like it.
As to sound quality…anything from Pass is more natural and warmer than the Benchmark stuff.
 

Just my thoughts.