Hi pottleflump,
Interesting idea
Unlike Dave I shall give you a slightly longer answer...
Yes the Tipo is pretty economic to run and drives really well for its age. But - remember your Stilo? The Tipo is a FIAT, not an Alfa Romeo. I suggest an Alfa 164... bigger, probably more expensive to run, but a lovely drive and really cheap to buy. It was the first FIAT-ised Alfa Romeo, which paradoxically enough, endows the car with a little more solidity and reliability than say the 33 or Sprint (when reliability was important the Italians used lots of German parts: engine management, gearbox, steering, even the seats!)
Labour is expensive (some jobs on the V6 take a long time) but you can balance this against the price paid and the standard of maintenance the particular vehicle has enjoyed. One thing about buying expensive cars when old is that they tend to have been better looked-after than cheap cars when old...
Or, a similar car - the Lancia Thema. I loved mine. Again, cheap as chips to buy. The V6 lives forever (it's a PRV V6, so effectively you're buying something of a mix between a Renault 25 TXE and a Volvo 960). There's quite a lot in NZ, always one for sale on trademe.co.nz, not sure how many there are in the UK. Most of ours are the V6.
If you do buy a Tipo, then at least try to get one without a carburettor, OK?
But I think it will be a little short on equipment compared with the other two cars I mentioned... for example, both my Thema and the 164 had climate-control aircon. You really do get a lot for around 500 pounds in your money...
You may also like to bear in mind that I am not completely talking out of my **** since I did own a 1989 Tipo DGT (from 2000 to 2002) and it was, well, OK. Nothing went wrong, though I did lavish some care on it changing belts, water pump, heater tap etc. But it was one of my least favourite cars to drive... and it seemed slower than my Uno 60, just very sluggish... They're popular cars and pretty solidly-built (and don't rust), but I reckon go a little more upmarket when buying an older car than what you have...
-Alex