6 weeks ago I bought a car from another member of the jewish community, when I purchased the car I asked him how long he thought it would last to which is responded ‘(u never know) but its a good car- just wear and tear requires a service every year like most part’, However just after 6 weeks of owning the car it broke down and now requires 3200 (AUS) to fix. I paid 1900 for the car and I am not expecting all of it back but I believe when you invest in a car for it to last 6 weeks is a little ridiculous.
do I have a halachalich basis to receive some money back (I asked for $750)?
Unless the owner was deceitful and hid from you some unknown defect in the car which may reasonably be assumed to be the cause of the break down, you would not have any halachic claim to a refund. Used cars sometimes break down in a way which require expensive repair, and the buyer takes this risk. For this reason some buyers insist on a warranty period which insures a minimum duration of a usable car. Barring such an agreement the seller would not be responsible.