Wedding Help

A little background on me. I recently made the jump from part time roaster to full time roaster & got invited to work a wedding after the previous vendor sold his business. I have a nitro coffee/cold brew coffee bike which they want as the centerpiece for the grooms table at the wedding. The wedding crowd is in their mid 20's and they are expecting between 300 & 400 people. I only recently perfected my cold brew recipe for the bike but never worked an event this big since I just purchased the bike last month. I was planning on brewing 5 gallons for my nitro tap and 5 gallons for my cold brew tap but I just received a request for 10 lbs of roasted coffee for the hot coffee being provided by the caterers which has me feeling like I grossly underestimated how much coffee I will need for this event. They will have soft drinks, beer & wine but my questions are;

How much cold brew coffee should I make so I don't run out? How much should I charge for the 3 hour event? Am I posting in the right subreddit?