Set yourself a series of goals or parameters.
are you building one set to do it all , be very good in the dob and equally ,if not better, as good in an f8 and up refractor.?
how wide of a field of view are your eyes going to be comfortable with?.
how much are you willing to spend on any one given eyepiece?
are you willing to buy used? or only new?
what are your observing interests? DSO or Planetary / Lunar observing? or a little of both.
In my case I wanted to do lunar and DSO both, I wanted eps hat were very good at f8 or f10 and still very good in my f4.9 skywatcher 12 inch, I have settled on 82 degrees as my max field of view, and also used or less than 200 d0llars ( no small feat on disability )
Im also not a brand specific type, but I want the best I can get, within my above constraints. So I have 5 TV, 4 ES, and 1 Meade UWA
none cost more than 200 used.