So any script kiddie can disable windows defender inside a PC with good group policies?. Defender I prefer it hardened, that a freeware antivirus. If you really are considering a security, setup Wazuh with sysmon alerta. A PC/instance with 2gb/vcpu for 3 agents is OK.
Maybe you can run X process AS other user with less privileges than SYSTEM.
I'm seeing there are various systems you can get into to pay.
First try to get a Residential Proxy, second there are various prepaid cards like Prex or payment systems like mercadopago (Brazilian company as I researched). Or search resellers.