Im trying to make this deck as consistent as possible (Pot of Extravagance is too much for me :/ )
If you like the look of graded cards, then you could grade it for aesthetic reasons
Garden of Freyalise is there to smooth out your mana and make sure you can play all the cards you draw, but the biggest upside is on the Disciple
To play a Pendulum monster, you have to place it not in the monster zone, but within a Pendulum zone
For individual cards and older booster packs and boxes, you will just have to gain a lot of experience and learn the nuances of real Pokemon products and then make educated purchases, ideally with a means of recourse if it turns out you were scammed (some kind of buyer protection program, etc)
This feels more like what Secret Lair should do if Wizards is going to make Universes Beyond this much of its core identity moving forward