Honda EU Inventer Generator. Super quiet.
Might be more then you want to spend but after 3 days you and people next you will be very happy.
Champion generators are not to bad. Find them online and at auto parts stores for about $350.
You will have to talk loud to be heard over it if next to you.
Might check with the event to see if it will allowed for you to run a generator.
Could be against fire code cause of the fuel.
M