Excel pro formas require manual input of every assumption. Three critical weaknesses: garbage in/garbage out (where did your $/sqft come from?), false precision (exact numbers hide uncertainty), and time-intensive screening (30 min to 2 hours per parcel).
API-driven data collection replaces manual research. ML cost prediction replaces assumed $/sqft. Auto-generated pro formas replace manual cell entry.
Initial screening (20+ sites): automated. Shortlist (3-5 sites): automated + your assumptions. Final underwriting (1-2 sites): custom Excel with actual bids.