How much should I expect to pay to fix my car?

And what happened when you unloaded the cement? If things went back to normal don't worry about it.

If it continues to ride low, go see your mechanic, he is the only one who can tell you what is wrong, and what the cost would be to fix it. In any event it surely won't cost as much as another vehicle.

See if you can get a free estimate. It's anyone's guess as to the extent of the damage and thus the cost of the repairs. The largest cost is the labor. If metal is bent and has to be bent back, the part that bent and was rebent will be weak and could be dangerous to drive. Insurance companies would total the car, meaning they would assume that the liability of allowing the car to stay on the road would be higher than the cost of a new vehicle even if the cost of repairs were not.

My answer: buy a new car.

If you're tight on money, drive it as is and save your money toward a new car. Sell it for parts or part it out yourself if you have the space. Often you can get more money on an old car by selling the parts than by selling the whole working car. Of course there is a lot of labor involved in taking the car apart to sell the parts. It might not be worth your time if you have a job. If you have time and not a job, then you know what to do.

Oh but for the ignorance of the proletariat, the common folk, as the weight limits of each vehicle which are not clearly stated in the car manual. Use Google Search to learn as to car weight limits AND tire weight limits. If one bag of cement weights 70 lbs. how many bags did "we" load into this Legacy? Oh, there is another aspect of the weight limits of a car. It a an axle specific weight limit. For the data you indicate it is possible "we" damage suspension parts, damaged the exhaust system, possibly the transaxle, overheated the engine and caused cosmetic damage to the rear of the car. The listing of the vehicle as a "2003?" year further indicates the extreme lack of involvement "we" have with this eleven year old Subaru. Furthermore, the quick grabbing of the smartphone to text here to invisible strangers to ask for guesses as to repairs further cements my assessment of partial culturally induced brain damage. In my book any time there is a concern as to the mechanical condition of a vehicle, THE first and ONLY possible thought is to take the vehicle to a certified and experienced mechanic. Guessing is not allowed as to car repairs. IF you had had some concept that cars have weight limits or even asked anyone, then the cement bags would have been in the back of a rented pickup truck and not on the Subaru. Only a mechanic can determine the status of this nice vehicle.

Oklatom has it right. If all came back to normal after unloading all is OK. Simply get on with your life.