1968 '340' Barracuda vs 1968 '383' Road Runner

Was it marketing that made the difference?
I was only 5 when the Mustang came out, but I remember getting diecast promo cars from the State Fair that year.
Chrysler always seems to be lagging in the marketing department.
I may be biased, but the 1967-69 Barracuda's excelled in any model, over the Mustang.
was the Mustang cheaper to buy?
The Mustang was a gloryfied Falcon & nothing else.