Thats the problem with Optiwhite tanks.
A 90cm x 45cm x 45cm would cost around the £350 area dependent on where you go.
That is just the tank, no canopy, lights, etc.
When you compare that to a similar sized Fluval/Juwel 125Ltr which would be £150ish with canopy, lights, filter, heater etc it means you have to really bothered by the clarity of the glass to spend the money!!!
I'm perfectly happy with my Fluval Opti-Green

I can see through it perfectly well. lol
AC