I would rate the progression system a 9/10.
And really the only part of the progression I dislike is the shop aspect. Primarily because it’s only a shop with real currency (USD, EUR, etc.) that’s converted into SanVan Bucks, but for in-game currency, ie Rip Chips, it’s not a shop, it’s a casino. You must take a gamble to potentially end up with the item you want, as opposed to being able to outright purchase that item.
The issue with this is, instead of being able to track exchanges and look directly into what your players are purchasing, you only offer them the possibility of purchasing what they want, and remove any ability for the developers (you) to see what’s most desired by your players.
Why is this important? Because, if you can see what players want, you can create special versions of those items purchasable with SanVan Bucks, driving even higher sales than if you were to hold engagement surveys asking what people wanted and making those items. You would essentially be removing an extra step between your playerbase and you, as you’d already know what the fans want, and would be able to create exactly what they’d purchase every time.
That is to say, the system you have in-place currently, obviously isn’t faulty in any way, I just think it could be improved upon to give you a better opportunity of knowing what a player would be most likely to buy.