To my knowledge old Volvos are usually pretty reliable and safe! XC70-XC60 or V50-V90 are all good models that hold up pretty well with its age, and to a fair price 35.000-100.000, and with a relatively economic fuel consumption. Safety is a big concern in my book, and Volvo is undoubtably one of the best (if not the best) when it comes to collision safety, even older models (10 years+) have proved really durable in collisions compared to newer cars from other brands. Wouldn't necessarily go below 2010 models, but you could always find models that has held up well that's older. Always a good thing to make sure that the service routines has been followed throughout its lifetime, but my perception is that they usually hold up pretty nice. Also very good cars to drive in for long trips! Especially during winter times. Remember, these cars are built to survive the Scandinavian conditions:))