Can I Photoshop and illustrator together

The other benefit is you get Acrobat as part of the suite instead of paying for it separately.

No, there's no special subscription for just two apps. You'd be paying for each separately. Based on current prices, Photoshop and Illustrator are $21/month each, so $42 monthly

Based on the pay-in-advance yearly subscription of the full suite, you're looking at $50/month. If you go on a month to month basis instead, it rises to $80/months, so you can see where the sweet spot is.

You can buy each single app, but it might become more expensive than the whole CC cloud.

No, there is no such plan. Simply buy a full CC subscription.

Mylenium