Coots,
If you want to save dollars and are handy on the tools
you could build one.
Myself and Baz (Bloodhound) and a few others have done
this.
My take on the
Joe Garlitz foam dome has a 3 ft side wall and
steps inside and out.
A 3 door system is used to have access and reach all parts of the
sky with the scope.
Pic 1 shows the 3 doors side on.
Small bottom door removes to stop having
to step over any obstruction in the dark.
Middle door is the lockable main door.
And the top door can either stay and run on rails or
just lift off also.
Pic 2 shows all doors off
Pic 3 shows the inside set of steps and the scope.
Steve