I'm starting out on what will no doubt be a long and expensive journey, but I'm hoping the end cost will be less that a dome purchase - which can start out at around $5k for something decent.
So, budget requirements led me to plan a skillion roof shed and have the roof "flip" on a simple hinged arrangement. I've obtained a bollard which will form the base of my pier and have to find someone that can machine and weld a steel plate on to that, then an aluminium plate separated by threaded rod for levelling.
I'm a little worried about flexure in the metal, but will just have to leave those worries alone for the time being and get the shed up in the first place, then bolt the pier in place on the slab - which is actually the top of my in-ground water tank.
Some pictures of how it looks now. In a few weeks I'll start to mark out the shed spot and get the family over for a good shed building and bonding experience