Low iron glass

[BT05]

There is another type of ultra-clear glass that is made by a competitior of PPG (I forget the actual name). In terms of grade, I'm not sure what you mean, but it does come in different thickness and can also be tempered.

I believe that the price of oil has a significant effect on the cost of acrylic. Not sure about glass, but it seems reasonable to assume this...

I got a quote from Bow Valley/Inter-American for a similar tank to yours and it was about the same price you were given. They do quality work but last time I talked to Doug he told me they were really busy and had huge orders coming in from local shops and from the US, so it might take a while if you go with them.