Bandit is right, you have to have a real passion for the hobby and a specific tank in mind to make it worth while mixing up your own water. I do it because I have extremely hard water, and I like high tech planted tanks and low tech shrimp tanks.... both don't really work well with very hard water, so I cut it with RO and boost some Ca and Mg to acceptable levels.
But, have I had luck in the past running both shrimp and high tech planted tanks in hard water....? yes, great luck, it's just easier with slightly softer water.