Drupal Commerce have customer choose how many items to buy
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.