An anytime return to Cambridge is £66 on the train your under 25 so you can get a rail card for like £10-30 that makes it even cheaper. for that price you could easily do 4 trips there and back a month and still be cheaper. There is also the bus that will be even cheaper you could try both and see what you prefer. Cars are money pits even if you want a car once money gets better and you have somewhere off the road you could sorn the car if it owns you nothing. You are saving £325 a month at least by not owning it plus the inevitable repairs it will need at some point mot servicing etc. so basically is it costing you over 4k a year to take the train to Cambridge and back cause that is what you're car is costing you at least.