BricsCAD
Octave (formerly Bricsys)
EUR 330–1,176 / year (approx. $385–$1,375)
RibbonSoft
$48 USD perpetual — or free · 2D · DWG via DXF interchange
The best value on this page by a wide margin, and it is not close. Forty-eight dollars, once, for a properly maintained 2D drafter that runs on Windows, macOS and Linux. It will not model in 3D and its DWG support goes through DXF rather than being native, so it is not a drop-in for a DWG-heavy consultancy. For everything else 2D — and that is most drafting — it is the sane purchase.
$48.00 USD for a single-user perpetual license. The vendor's wording is that "you can use the software for as long as you decide to keep it." The store has a currency selector covering USD, EUR, GBP, AUD, CAD, CHF, CNY and PLN, so you can buy in your own currency. Continued access to updates after year one costs 70% of the full price per year, and is optional — the license you bought keeps working whether you renew or not. QCAD Community Edition is free and open source.
Vendor pricing page: https://qcad.org/prestashop/en/qcad/20-qcad-professional.html
For scale: AutoCAD is subscription only, with no perpetual option at any price since 2016. Autodesk publishes its current rates at autodesk.com.
Pricing and specifications: https://qcad.org/prestashop/en/qcad/20-qcad-professional.html