V70 Help how far do I go?

[ians]

I have a c30 R design sport which I have enjoyed but needed something bigger and bought a 2002 v70d5. I know the engine well having had a s60 some years ago. I didnt pay much £750 and the guy had it 8 years 155 000 mile. I had it serviced and turbo oil return pipe fixed 200 quid. they told me brakes are needed all round cost again 200 quid. Next job is cambelt I thought it had been done in 2013 but no paperwork and feel I cant take a risk last done at 82000 miles cost again will be 250 ish. The car runs well and very relaxed drive I do like it. Now the question do I sell it on now or change cambelt, 2 tyres, recharge air con and lastly the gear change between 2nd and 3rd if you rush it you get crunch noise. I feel a bit stupid buying it but it was cheap and once the jobs are done it's a really useful car giving around 50 mpg. What would you guys do repair or sell on advice needed.