Thanks a bunch for playing and you reflective comment.
Regarding how to earn more gold in a run, the intention is that it depends on your boost level when you hit a treasure run. Doing more back flips increase your boost level for a while, which in turn increases how many gold-ores you can crash into when during the treasure run. The gold ores in the treasure run gives significantly more gold than the single pick-ups throughout the level.
However you are absolutely spot on regarding the pricing in the shop. We didn't manage to balance the shop economy properly, which is probably the pacing issue you experience. Before we submitted the final build, I actually went in and reduced all the prices in the shop by half, in an attempt to remedy this, but unfortunately, it wasn't enough. We'll be pushing an update after the jam with a more appropriate shop economy which hopefully will improve the pacing a bit :-D