It would depend on the size. I got a custom cut lid for my 80g angelfish tank, and it was $35. I also Got a 2 pane hexagon cut lid for $15. It would be faster to have them cut it, than to cut it yourself. You can also choose what thickness you want the glass to be. The problem is that when glass is cut for you, if it is a few cm too long, sometimes the shop won't adjust it for you and you get stuck with a piece that doesn't fit like you want it to. Plexi glass on the other hand can be hand cut at home, and adjusted as needed to fit your tank and is much cheaper in the long run.![]()