Cattleya walkeriana and nobilior -- down the rabbit hole

[MJG]

I have fallen head over heels with these two species. Reading online to try to fill in some blanks has led to confusion. I'm a newb so bear with me.

First, walkeriana. You can find some of the different color forms for sale online but it's very confusing. For example the alba form. Some sellers list theirs as Catteya walkeriana var. alba. Period. (Or f. alba.) Others modify the nomenclature with 'Pendentive', 'Kenny', etc. and describe specific attributes. I assumed those were culivar names. Then I read that 'Pendentive' isn't fully walkeriana, it's partially dolosa. I also read that the "real" walkeriana f. alba has a pure white lip, not any yellow. Anything with yellow in the lip has some hybrid in it. Really? And prices are ALL over the map.

So if you buy Cattleya walkeriana var. alba 'Pendentive' AM/AOS from Hauserman for $20, you're getting a bargain, but not a walkeriana? I bought a Cattleya walkeriana f. alba x sib from Marlow. It will have a yellow disc on its labellum. Is it really a walkeriana? And so on.

So how do you know what's actually a species walkeriana?
How do you know what you're actually getting from a seller?
How do you know what's a fair price?

I get further confused by the other color forms.

And finally, what is up with nobiliors? I spent 2 days searching online for a nobilior for sale. All I found was a few "sold out" listings. Why are walkerianas in some color forms and particularly nobiliors in any color form so hard to find online? Is there another source besides vendors online?

For now I'm just trying to get a few inexpensive ones to learn on. But geez.

Ok, that's a lot of questions to one thread. Maybe verging on a rant. Thanks!