Vertigraph offers perpetual licenses for BidScreen XL ($799) and SiteWorx/OS ($2,999). You buy the license once and never pay a license fee again. Year 1 of Full Serve maintenance is included; from year 2 it is $199 per seat per year and it is required to keep using the software. If Full Serve lapses, the seat stops functioning until Full Serve is renewed, and renewing restores it.
Most takeoff vendors retired perpetual in favor of subscription-only over the last 5 years. PlanSwift, On-Screen Takeoff, ProEst, Procore, and others moved to subscription. Bluebeam went subscription with Revu 21. Vertigraph and AGTEK still offer perpetual licenses.
Total cost of ownership over 5+ years usually favors perpetual when both options exist. A $799 perpetual + $199/yr Full Serve for 5 years = $1,595; a $1,749/yr subscription over the same period = $8,745.