Bought a secondhand car off my sister in November, only really use it twice a week or so. It cost £3000 - wasn't really worth that much, but I don't like screwing over a family member and she needed the cash.
It started making a funny noise recently, so I took it to the garage. It's the catalytic converter and it's going to cost £1000 plus there's one other thing that needs doing, bringing the total to £1200 
I don't really have this much money, but I could put it on my cc and pay it off in installments of a few hundred quid over the next couple of months.
If I don't pay it, I feel like I'll have chucked away the three grand on the purchase price, not to mention my car insurance for the year. If I do, I'll be scrimping to pay it back.
Have told them to fix it but have a sinking feeling in the pit of my stomach... AIBU or WWYD? :(