That’s an awesome trade as a kid tbf, would’ve done that too x3

Im not sure if this is an option everywhere, but in my country you can add your phone provider to google play as mentioned

So if you had nicer parents that topped your plan off for one of the more expensive plans what you could do was get a cheaper one, and spend the leftover on in-game purchases or whatever through google play :3… phone plans were also how all the illegal irl item trades in mmos were done ^^