I work for a General Contractor and we put a back lit glass floor in a recent job we completed. Profile of the glass was 2 layers of 1/2 inch, 1 layer of 3/8 inch, and a 1/4 layer with a anti-slip surface. All layers laminated with a PVB interlayer for strength. Basic module was 5 ft by 5 ft nominally. There was also colored inter layers for aesthetic purposes. Total glass thickness was 1 3/4" nominal when all said and done. The pieces were approximately $200/sf when shipped from LA to DC. Note that this was in a public assembly building and it is engineered for heavy traffic. Not sure if you could get away with a single thick piece or not. Either way, I would think it would be cost prohibitive. PM me if you want to know who we bought it from.
I need a glass floor and was told at 4ft span 1" would be needed, but their price was $225 at that thickness, can you share where you got your 1_3/4" for 200? Hoping they have a good deal on 1"