How much does it cost per person we have 11 maybe 13 in our group going in mid July?

Check groupon or call for group rates.

Definitely check online because you can get a discount.

We paid around $80 for the 5 of us. But that was online; not sure about in person price.

I will recommend you to buy tickets online. Check it out here. https://chicago.legolanddiscoverycenter.com/tickets/group-tickets/

I'm not sure I had a coupon.sorry