A few years ago I used glass beds. Not fancy ones, I got a large cheap mirror from the hardware store and a glass cutter. Both combined were cheaper than a single bed meant for 3D printing and for PLA they lasted multiple months. PEI is just more practical since it won´t randomly break and is flexible making part removal very easy.

I ruined it by trying to print PETG on it without any adhesion layer in between. It took out a nice chunk of glass from the center.