I still reckon for 3.8k you can dig a bigger hole and knock up a slab extension, some pillars and some bricks craigb. of course for that price you'd have to do it yourself... I would...
character is a layer of shavings, a dirty window that a mate has written "wash me" in dust, timber, machine oil, a few empty tinnies, a few knocked up chairs for mates and the smell of wood dust. NOT how old, dirt floors and cramped conditions. I'd rather have silentc's box and deck it out - possibly like major with the ply walls for hanging stuff etc,
I reckon a nice big tin shed, some batts in the roof and walls, ply panels, an aircon, a couple of windows, 2 racks -one for timber and the other for clamps, a roller door and a human door for airflow, an exhust fan, a lean to for the dusty that purges externally and a german shepard to lay in the dust and eat pomerainians and stray cats. stuff being under the house in a ratty little corner with no power except by an extension cord buddied by multiple doubel adaptors. this is after all the 21st century.
tell us craig (for real) would you swap your tiny little shed for silents tinny ??