Ian in my game has literally 2 coins in his pocket, and this is only because he won the pool game bet early on and didn't give up on the stipend from dad.If he did, he'd be very much broke right now. So, no, i can't say i share this view that he is "always swimming in cash", it definitely doesn't feel like it.
For the record, Ian's options to spend money:
* paying for drinks during date with Cindy in Ch.3 ($1)
* bribing the bouncer in Ch.5 ($1)
* trip with Alison in Ch.9 ($2)
* footing the bill during date with Alison in Ch.9 ($1)
* clothes in Ch.9-10 ($1 per outfit, up to $4 total)
* access to Lena's Stalkfap Pro in Ch.10 ($1)
* good wine for Alison date in Ch.10 ($1)
* trying to pay for sex with bad Jess in Ch.10 ($1)
* tournament fee in Ch.11 ($1)