Questions about Epson 603 Multipack

Can't you offer noname variants, you can get them at temu for 13.- (b, cy, y, m)

The Epson 603XL Multipack (M, Y, C, BK) is available in 2 variants. A normal version (C13T03A64010) for 62.50 and an XL version (C13T03A64020) for 70.40. In the specification, both are listed with 20.40ml. What is the difference (apart from the price)? I can't find the manufacturer's number C13T03A64020 on epson.ch.

Why are you going up with the price?!

I'm hesitating between the ordinary and the xl cartridge. But I'm afraid it won't work. What is the difference between the regular and the XL? We do a lot of black and white copying. We change the black cartridge every month. What do you think?