I think the hourly rate is a good idea. A flat rate can always be easier to explain to the client, but often times you will end up going over because of variety of reason like excessive changes. For basic video production, I’ve seen a rule of $1000 per minute but it can’t be the rule of thumb for everything.
Chicago Video production | Chicago video marketing | New Slate Films
Check out http://www.newslatefilms.com for cinematic marketing