As far as pecking order for prices...in Cudas the 71 is the most expensive, followed by the 70. The 72 is probably next, due to the bumpers not being equipped with the big 5MPH guards. Then the 74, due to it's low production numbers, followed by the 73. The 72 thru 74's are all similarily priced, while the 70 and 71's are a big step up for a comparable car. No factory big blocks after 71, the 340 lived until 73...72 340's have forged cranks, 73's have cast cranks, the 74 came with the 360, which was actually rated higher HP than the previous year's 340.
You can get a nice 72-4 for what you'd pay for a project 70-71....just depends on what you like and are willing to spend. As an example, my 74 is a rotessorie resto car that I'm thinking of selling, I'll probably get low 20's for the car. Good color, 360 auto, a 2 fender tag car, non numbers. A similar 70 would probably go for high $20- low 30's, a like 71 for mid to upper 30's, maybe 40K. Just an example of the pricing on these cars.