Check the cambelt & tensioners have been done & don;t take their word for it, if they haven't got the invoice for it then it hasn't been done (I learnt the hard way).
If it hasn't been done, the price is OK to get it done & make it worthwhile still getting.
Check ALL the electrics incliding indicators, dodgy functioning means dead body computer, another pricey fix that I've had to do.
There's a decent 147 buying guide here;
Alfa Romeo 147 Buyer's Guide