The price shown above the variation is the woocommerce product price, so if you hide it then price from all the products will be hidden. The price above the button is the variation price so you can hide the variation price by using the below custom css:
.single-product .woocommerce-variation-price {display: none;}
Now if you remove the previous css and add this new css then the product page will look like this:
Single product page without variation:
http://prntscr.com/bx85z1
Single product page with variation:
http://prntscr.com/bx86e5
But the reverse is not possible because HTML structure is same for the price.