3 - 4 car workshop garage suggestions?

[300bhp/ton]

Can anyone advise on some kind of stand alone building to hold 3 or 4 cars? Looking for something pre-fab most likely. Maybe a bit like a small barn or large garage/workshop. Not overly fussed by material, although metal is fine.

Looking towards the budget end of the scale. And will be being put in a field, although happy to make concrete pads for main support/feet. Floor will probably be initially rubble/hard core.

[V8RX7]

Take a look on Ebay several steel building co. advertise on there - appear to be good value.

Be aware they aren't that secure as std, if that matters.

Sometimes there are decent used buildings on there too.