LF 4" diamond glass holesaw. Calgary

[Tigweldpro]

I am looking for a 4" diamond holesaw to make a hole in a sump part for a filter sock. anyone have one I can buy/borrow?

I see new ones for $50-$60 but I only forsee ever using it for 1 hole.
Other options could be use acrylic(but bonds poor to glass with silicone) or have a go with the waterjet table at work but it etches the glass and makes it real hard to clean algae off of it.