While most Pokemon card sets come with individual booster packs, the 151 set is a special set that only comes in boxed sets such as the Premium Collection
If you priced things well then you should be getting enough profit that the occasional refund to make things right wont break you
Since there are so many strong options in the Masters Of Evil deck - both traditional artifacts and artifact creatures - having a way to get whichever artifact you need at any given time is excellent
If you need some backup attackers, Volcanion , Mewtwo & Mew- GX , and Blastoise & Piplup- GX can all make a splash in different situations.
Lotho, Corrupt Shirriff Lotho, Corrupt Shirriff plays quite well despite the almost-identical Monologue Tax feeling like a dud most of the time
Any activated effect goes infinite with the staff so long as you have a free sacrifice outlet like Ashnod's Altar