I'm doing a student playthrough at the moment to see how it differs. To be honest, the money isn't as big of a deal as I thought it would be. I had enough money as a working adult to buy all of the stuff and try it out and found that most of it ranges from slightly helpful to complete waste of money. For example, food expenses, I thought I was gaining favor only after much money was dumped into that did I finally decide to test it and find that it had zero effect. This time she can live on cup ramen, she gets enough protein in her diet already *wink* *wink* *nudge* *nudge.*
Condoms are pretty much the only thing I'm dumping money into right now and I'm power leveling Imouto's stats.
That reminds me, the creator of XCOM and XCOM2 said "if given the chance, players will optomize the fun out a game" and while I can see where he is coming from, I think part of the fun is doing something again but faster and better until you're so skilled that you can pull off that perfect run. If you never got any better what would be the point of a second playthrough?
I'm thinking of doing, while not a walkthrough(I couldn't do a very good one for a sandbox with so much RNG) it would be more of a tips and tricks, but I'm not sure if anyone would be interested. I mean you've either already played it or you're not looking to pick it up.