Mine isn't a ranked list. but here are things that count.
Colors, price, features, fit, overall look.
For any single buy. At least here in California if you do long rides in the summer you need a jersey with a good full length zipper. So that pretty much controlled for one buy. (Of course not black and price counted, but the buy happened even if not cheap).
I find a steal I may buy, depends what I have, but having a junk jersey is as useful as a clunker for riding when you don;t want to expose your good bike.
Hey if I like it lookswise enough I'll but it unless a total ripoff. My SFVBC (local social club) jersey fits that. It was pricy, but not as bad as some club jerseys. It had to be since it was a special order. Same for my LA Wheelmans jersey. I have a Land Rush Jersey. I honestly do not remember if it was included or extra. If extra it was at a nice price, but available only to those who did the ride. I would ahve bought it at anything less than rippoff.
And a fair pop of my jerseys were determined by color. When I ride alone I want a jersey where if some jerk hits me he can't say he didn't see me. That he was blinded by the glare perhaps.