I feel for your financial situation, but it just seems like you’re taking a HUGE risk by buying a refurbished device. It’s possible that the seller has embedded a hardware or software malicious program that will be able to access everything you do on the phone.
You think you’re getting a good deal buying a refurbished device, but it seems too risky to me.
I’ve seen people sell old SSD’s and HDD’s only for their data to be recovered by data recovery experts and they get access to their personal user data…