SotaProxy (sotaproxy.com) puts five proxy types on one balance: residential traffic billed per gigabyte, dedicated datacenter IPv4, static ISP addresses, IPv6 and rented mobile modems with carrier IPs. The residential network covers 220+ countries; static addresses are sold in several dozen countries.
Residential traffic costs $2.00 per GB on small packages and gets cheaper with volume: 10 GB for $18, 100 GB for $150, 2000 GB for $2000. Unused traffic does not expire while the package is active. Datacenter IPv4 is $1.80 per address per month, falling to $1.15 from 75 addresses; ISP is $3.00, falling to $1.90 from 200 addresses. IPv6 costs $0.20 per address per month, and mobile starts at $5.76 per day depending on country and carrier.
The balance is topped up with cryptocurrency from $1: 34 coins are accepted, including Bitcoin, Ethereum and USDT on TRC-20 and ERC-20. Cards and invoicing are not available. There is no free tier, but support can open a trial package on request, and the WELCOME10 code gives 10% off a first order.