A network to support 8500 devices in pockets with a few hundred geographically dispersed low bandwidth users, and a few tens of high bandwidth users, requires a very different design than a network to support 90-120 high bandwidth users in a 120M^2 space.
On 1GbE vs 10GbE, it really depends on your network design, and available budget. If you've got 200 3x3 Radios hanging off a stack of switches you are going to need a 10GbE backhaul to your core/controller to be able to support the likely load you've designed for. However if you've only got a few APs per lightly loaded switch then a 1GbE backhaul is sufficient.
This is the old two-dresses problem. "I've seen a dress for £80" ...that seems a lot... "but I bought one for £40" ...thank goodness for that...
I like the fact it says £15,000 for a 500-pupil school, that way at £8000 I can do it for half the price. Where's the Ruckus catalogue gone?