More expensive = better?

As others have mentioned there is a law of diminishing returns when purchasing more expensive gear.

When I am evaluating new components I compare what I am shopping for to my reference (my current system)

I believe that audio gear is much like wine.

A 2018 Pomerol or Saint Emilion Grand Cru is fabulous, but is it twice as good as a bottle that is half the price?

No. It is almost always a case of diminishing returns. 

No it won't. Not jaw dropping. Why should it?

In fact it might not even sound better than a $100 one.

It's far more important to match the amplifier to your speakers in terms of power and drive.

A second opinion, preferably a non audiophile one, might also prove invaluable when auditioning.

Bear in mind also, that certain features can prove useful, eg a mono button or a balance switch etc.