That's the thing, even used Pixels are almost twice the price of what I paid for my new phone.

Back when I bought my phone I considered that route. but then since I can't replace the batteries on new phones without risking destroying the device. And there's a big probability that the phone comes with an almost dying battery.

I also understand that GrapheneOS can't be installed on any "unlocked" phone, it needs to be OEM unlocked and most sellers don't know/specify, so ended up considering too expensive and too much of a risk.