Turning expenses into cashflow?

[James P Fridge]

Let's say I purchase a 4 plex that rents for $2,400 a month. It has a new roof, 4 new a/c condensors, 2 new water heaters and tile throughout. My PITI totals $725/month. I take that $2,275 left and put it in the bank to build up reserves. I end up spending $2k on maintenance and a couple water heater that year. I had no vacancies. Which gives me $25,300 in the bank for my reserves. I'm guessing that should be plenty of reserves for that property, so I start taking $2,275/month I have left after PITI and put it in another bank account. When I get enough, ill put a down payment on another property.

My question is, does it matter all that much what my cash flow is per month? Especially with multifamily, where my expenses are higher, but that money is going to be saved for reserves anyway. If the property is sound, the main capex items are new and I manage it myself then the expenses will eventually turn into cash flow, once I have enough reserves. I know there will be surprise costs. But it seems, to me, that getting $100 or more per door isn't that important when im saving 4 times that through "expenses". And once I'm satisfied with my reserve amount, then everything not PITI becomes cash flow. I'm curious about this, and i havent really seen it addressed. Am I being way too optimistic about this? Am I leaving something out? Is super high cash flow really that important? I'm new to this, so don't beat me up too bad for it. Thanks!