I disagree with you, Assassin’s Creed’s financial system was laughably inadequate. With the exception of ship building (in AC4), wealth was a worthless pursuit which should never be the case in a sandbox game (unless it’s zombies or something). The original AC didn’t get into money (which worked) however, as soon as AC2 came along so did the terrible economics that they implemented. Money was as easy to obtain as walking past someone and it only could be used for two things: better gear or making more money. Seeing as you shouldn’t play the game as a hack and slash (makes the whole thing boring), buying gear doesn’t mean anything. So money is pointless in AC2.
AC: Brotherhood and Revelations had a similar problem (no worthwhile gear, money to make money) but they’re not the worst offenders of this series. AC3 had the worst economic set in AC history. Not only was upgrading gear pointless (unless you really suck at the game), the whole ship mini game was set up just so you can make more pointless money which you would then use to buy more pointless things to make more pointless money…
I like Assassin’s Creed but let’s not even pretend it has anything resembling a realistic or intuitive economic system.
And Dark Souls (1 and 2) is infallible.