Every designer has its own design process, specially when it comes to branding design. The price will vary depending on the work required, if you need business cards, branding applications (tshirts, flags, stationary, etc).

Charging you $600 for a 4-5 hour work, its just symbolic. The amount of work put on a logo easily takes a couple days if not weeks to come up with the final design.

For instance, Comedy Central was charged $1MM for their logo redesign and the agency charged them for just "1 hour" of work. This doesnt mean they normally charge $1MM per hour.