RE: Reverse Holos
Back when I was collecting that way, I tried for the master set. Every common, every uncommon, every rare, every holo, every reverse holo, every ultra rare, every theme deck exclusive, every promo. I went the master route.
Of course it started becoming rather expensive and I couldn't really keep up on that, that ended about the Emerging Powers time frame. I still collect on the promo route, which for me isn't just the black stars but the trainer kit cards like the cosmos Talonflame and the shattered holo cards (still missing a few there).
I also work a living card dex, but with that one I try to have everything holo or reverse holo that reflects both of their types if doable and applicable and if they have EX, LV. X or Prime versions those are in there. It sometimes causes conflict though, as was the case with Lucario having a Lv. X in Mysterious Treasures and then having an EX in Furious Fists, of course all of those being fighting types. It also contains the M. EX cards, and the special cards like shiny, crystal, LEGEND, Gold Reshiram and Zekrom (will at some point have the Full Metal Dialga EX) as well as the a 'pokedex' of the Delta Species pokemon (which personally I would love to see make a return).
Not sure of the math on the reverse holos but I can believe they are probaly rarer...relatively speaking anyway. A regular holo will still usually be worth more than a reverse holo and of course something like an EX will always be worth more. There are times, despite any math, that it seems some regular holos are worth more than the reverse.