No laptop/borrowed only: $5-10 USB drive + per hour rate - just go to any internet cafe and pay the usage rate or one of many US public libraries that provide free computers.

Cloud-only, low-end, severely limited dev (if on extreme budget): $179 currently: https://www.laptopmag.com/reviews/laptops/samsung-chromebook...

non-Microsoft dev who doesn't like tinkering: $999+ https://www.apple.com/macbook-air/

Microsoft dev or tinkering Linux dev: $800+ XPS 13 still a good choice http://www.dell.com/en-us/shop/cty/pdp/spd/xps-13-9360-lapto...

Security-focused dev: $1199+ Librem 13/15 https://puri.sm/

Or: buy refurbished, but don't skimp on specs.