I did this in our old house using 10mm toughened glass set into ally channels in wall and floor and a slot in the ceiling so all top fittings were in the void between first floor joists
Depending on your situation you may need to use fire rated glass ( if you have aloft conversion ) which then becomes mega money
check with local building control as too what regs they will req
cant comment on costs as mine was done on the cheap as I have good trade contacts – all in about 1500£ materials – installed myself