Last HP sale was +30%. If you buy the $100 package, that’s 6,000 more HP. That’s two 4* covers and a roster slot or two (depending on how big your roster is) for free. I’ve still got $100 worth of gift cards in my wallet from Christmas waiting for a sale.
I hope there is someone in your area who can give you a hand. Sounds like you are willing to learn and help out. Just need some guidance and help.
Just FYI - If you do some searching, there are frequent sales on iTunes gift cards ($5 off $50, $10 off $100). That savings plus an in-game sale is a pretty significant discount.
No one should need help spending money. 
I did not read the OP (will probably later), but just wanted to write something silly (not that I write clever things usually some would say 
).