For under 15 attorneys, Clio or MyCase ($39-$139/user/mo) beats every alternative — the $180K+ custom build won't amortize at that headcount. Clio with trust-accounting add-ons covers up to 50-80 attorneys cleanly. Enterprise suites (iManage, NetDocuments, Litera) pay off above 100 attorneys or when document-management volume exceeds 500K matters — the per-user fees plus implementation start looking cheap against Clio's scaling gaps. Custom builds win when the firm has a proprietary practice model — high-volume consumer law (immigration, personal injury), LegalTech startup, or in-house legal ops with $15M+ matter spend; break-even vs Clio lifetime cost is typically month 30-40 at 100+ attorneys. Above 300 attorneys, custom + integrated e-billing (Serengeti, TyMetrix) usually wins.