I've picked up one of those Ceboras for £65 that had been used about 3 times back in 2007.
Cebora is the OEM, the exact same welder can also be found secondhand badged as a Snap-On 130 Turbo (which I have here, bought s/h in NI for £75) and a BOC MigMaster 130 Turbo (which I had many moons ago circa 1991 (£199)).
I would hunt for a s/h one for £150 and spend the rest on trying to get a fixed priced/non rental cylinder of shielding gas (argon/carbon dioxide/oxygen mix) and some clamps and consumables. Rental from BOC/Air Products is okay if you do bucketloads of welding, less so if you do bucketloads one month and nowt the next.
Still fancy a PortaMig 180 though.