Drupal Commerce have customer choose how many items to buy I would like to give my customers an option of how many products to buy.
So I would like to have a page (or view) that gives the user the option to but 1, 3, or 6 items of my product each with a little more discount.
For example:
 1 for $3.50
 3 for $7.50
 6 for $10.00

And have those three options displayed next to each other.

Also, I would like to give the customer no other quantities. It is either 1, 3 or 6 items that they can buy.

Anyone knows how to do this?
You could just create 3 separate products in Commerce to represent each quantity. This makes sense especially if you only have a few like you describe. Each "bundle" product can have it's own SKU/model number, and it's own price. This also provides historical record, if you change your bundles in the future, you can keep the old SKU but archive it, and make a new one to represent your new pricing/quantities.