So are the Zinfandel better because of price no idea.
Nope. CS is typically more in demand, and gets a correspondingly higher price. Price can be an indicator within a given varietal, but it's not a guarantee.
As
@Jim Welch's said, most of us are flying blind, and those that aren't, are dependent upon Mother Nature and Dionysus to provide good grapes (good tending and care matter greatly, but Mother Nature has the final say).
Post-fermentation blending is probably the best course of action, but it requires enough space to have carboys (or barrels) of each wine. That doesn't work for everyone.
My 2020's are field blends -- I researched grape varieties and went with a Bordeaux bend and a Bordeaux blend + Zinfandel. I knew a Merlot-heavy Bordeaux blend would work (hundreds of years of history behind this decision) and tasted a Bordeaux-style blend + Zinfandel and liked it. The latter had a higher element of risk, but it worked out.
This year's plan is different -- the plan is an 8 lug batch each of Tempranillo and Grenache, and a smaller batch containing 1 lug each Syrah, Mourvedre, and Petit Verdot. After bulk aging, the blend will be blended into each of the Tempranillo and Grenache, according to taste. This mixes the blend types -- doing post-aging blending with a field blend.
However, it fits my space and I have confidence that the final results will be good.
If you're buying red Vinifera, you can make something you like. Don't over-think this, as it will drive you insane. Make a selection based upon research and plow forward!