I was thinking about this more, and you can probably get better value by using the gems on opening packs IF you dont mind what bowlers you use. Because you will get more cards overall, but they will mostly be common players because you typically have to open loads of blue bags. So only do it if the players you want are common type. you can probably reach a higher levels faster doing that, but with worse bowlers. There are some solid bowlers in that common category though, so not all are bad.

I do also wish this sub was more active to discuss the different approaches. Personally I favour investing into specific, more difficult bowlers and my bat. But others may use different strategies.