If the 6 cylinders had 4 valve cylinders and were supercharged or turbo charged, they get the same or better power output as an old V8. More complicated engine but more horsepower output. They also get better gas mileage. This is the reason the V8's have gone out of "style" with a lot of people. Also, the mandatory fuel mileage requirements by congress.
Cars and trucks are expensive these days. Might have to wait and get a late model used one. The economy is tanking.