Is there a way to active specials with coupon

Hello I only want to active specials with a coupon after an X amount of products are in the cart. Can this be done and how
or make all prices the same after x amount of products are in the cart.

ex

in cart
product x I have 2 of, $4.00 each
product y I have 1 of , $6.00 each
product e I have 3 of, $ 3.50 each

making it a total of 6 products at $24.50

now I want to change it all to $2.00 each after a coupon which only works when you have 6 6or more products in the cart making price $12.00