BUY nearly new with 5 - 20K on clock (50%-60% of new price)
SELL 4-5 years with 60-80K (third of new price)
that way you get the best out of a car with minimal depreciation, only one or two cheap mots, one set of tyres and pads, but no shocks, clutch, discs (if lucky), exhausts etc.
e.g.
1) Xsara HDi 12K list, £5900 @ auction 18 months old with 10K, run 3 years & 40K, sold for £4500, virtually no depreciation, no problems, no expense bar a handful of basic services & 2 tyres
2) Reno 19 RSi Turbo D, 12K list, £5900 2 years old with 19K, run for 70K/5 years with no major expense, sold for £1500. that's only 4400 loss in 5 years!
BOTH 'kin cheap motoring!