Found a place that lets you pay for audio recording of an orchestra online. It's not what Clio used but should give a decent ballpark for the costs involved:
Book a shared session with a Symphony Orchestra 50 pcs. Shared Session allows you to record an orchestra at an affordable price. It is the best option if you need to record a short piece of music.
orchestrascoring.com
30 mins is enough for a 30-second ad or a short teaser, and costs about $1400USD. Clio had about three to four minutes of orchestral recording, and add in video footage, so I'd guess around $10K for the concert piece all up. I think it was worth it - it set a really good first impression to start the debuts off, and fit Clio's tone and style really well, from what I can see. Good job on that, Fishman.