Most deals that go sideways do it on the costs people skip at the kitchen table. I run a property the way an owner has to live with it: real rent set on what comparable units are leasing for this month, a real insurance quote on this specific address, taxes after the non-homestead reset, plus vacancy, maintenance reserve, and management.

The line items that decide it

Insurance is the big one — never trust the seller's old policy; their rate is not your rate. Property taxes reset to market on a non-homestead purchase, so budget the jump in year two. Check the HOA for rental caps or tenant approval before you offer, and confirm any CDD bond on top of dues.

Cap rate vs. what actually hits your account

Cap rate is a quick yardstick; cash-on-cash is what you feel. I'll show both. If the property cash-flows, you'll see the math. If it only works on a spreadsheet that ignores insurance and vacancy, I'll tell you that before you wire a deposit — which is the whole reason to run it with someone who manages rentals, not just sells them.