Well on the plus side there is a lot there to work with meaning all of the things that would have to be rebuilt, restored, fixed are basically present so a person would have to search for them.
On the negative side, that hit on the drivers door was hard and I would be surprised if the lower rocker and frame are not buckled some. They can be fixed on a from rack but it will take a little bit of work.
As to the value; unfortunately it is probably work more in parts (but not much). If you are buying and want to build a car you will keep forever, then it might be worth around $5K, however if it is car you are thinking of "fixing and flipping", you will need to get it for $1-3K to make it even close to being a "deal". As stated, it is going to cost quite a lot to get it even close to right, especially if you are going to have to pay someone to do the work. If this is the case, save your money and find one that is done.
All this said, 72-74 Cudas (Barracudas included) are getting pretty good money if done right. I attribute this to the fact that other than the round taillights (which I personally prefer); there isn't huge differences between them and their 70-71 brethren. Yes I know the difference, but the causal buyer/investor doesn't seem to know or care as much.
Bottom line is that this car has a lot of hidden issues that will have to be dealt with, rust anywhere means there is rust elsewhere (might be minimal, but it is there). The hit on the drivers door could be a blessing as well as a curse; blessing in that it will scare off many, curse in that there are probably other hidden problems (buckled floor, buckled rocker, damage to the rear suspension attachment points, etc).
Hey, a beat up Cuda is better than no Cuda...
Save the planet and restore/rebuild the car; its just money (I say this in earnest, I have of $45K in a 73 Barracuda myself and am not done yet).