Bought the building for the dirt under it, and the rent turned out fine
The listing was a 9,200 sf single story office on 1.4 acres in an inner suburb, built 1978, three tenants, asking $760k. I looked at it because of the land, not the leases. The parcel is zoned in a way that allows a lot more than a one story building with a big surface lot, and the county assessor had land alone at a number that was more than half the asking price.
What I paid: $665k, so about $72/sf on the building. Tenants were an insurance agency, a small accounting firm, and a title office, all on gross leases with rents between $13 and $15/sf. Gross lease means the tenant pays rent and the landlord pays the operating costs out of it, so my number that matters is what's left after taxes, insurance, utilities, and maintenance.
Year one collected rent was $118k. Operating costs ran $54k, higher than the seller's sheet because he had no line for the parking lot or for vacancy. Net was about $64k. Not thrilling on $665k all cash, but it's positive, and the tenants have been in the building longer than I've been investing.
The part that nearly broke it was the roof. Inspection called it five years of life, my roofer called it two. I held back $40k at close and spent $31k in month eight.
What I'd keep: buying where the land carries a real share of the price. If the office use goes away in ten years, I still own a corner of a suburb. If I'd paid $72/sf for a building on ground worth nothing, the whole bet would be on leasing an old building forever.