To answer your last question I think it is a fair price for sure.
If you really haven't seen a lot of mushrooms I can recommend what I do to get an idea of what is out there and check out a lot of online vendors. To sell their stock they need to list pictures and you can get an idea of what is out there-
some of my favorites are liveaquaria.com ****************** sealifeflorida.com and there are tons of others- the banner ad at the top often has an interesting online vendor. This is one of the few sites where I actually want to click on the ads!
mushrooms come in nearly every color and most are really very easy to care for and will do fine in low light. (PC lights) and will also thrive in very strong lighting if properly acclimated
I think from my own personal experience dealing with my local fish stores and some online vendors is that there are some vey basic mushrooms typically actinodiscus kind that are in the less expensive range - mind you some colors are deemed "more rare" than others and will usually cost a few bucks more.
there are very common greens and sometimes reds and purples- many seek after blue as it isn't as easy to get...
But then there are ricordias - more texture like dippin dots, a little pricier.. care is still the same- the Yuma type (bumps on the mouth) can be a little finicky if it is wild caught. If its a florida type (more concentric bumps, none on the mouth) it will sometimes have blue as a common color .. its very strange. Depends on the vendor, I think.
There's some crazy rhodactis types out there - some called bullseye some called UFO.. I learn about all these by drooling all day long looking at these things
If you can get superman mushrooms - they are usually blue with red specks on them (its more of a term for the color than the specific mushroom species) i'd say grab them. I haven't gotten some yet and in some areas they are common, others very rare. If you enjoy them and feel it would be a good investment? Go for it!
Just nkow that what you can get locally versus online will probably have a huge cost difference. You can find exotic things online but usually for $$$$ but if you find something local you like and its cheaper? Well unless I am suffering from an impulse buy on something i can't live without i usually try to stay local to help support a good business we have nearby