Deferred payment = bad
Royalty payment = unknown

Fee, paid for finsihed video = normal

How would you work out a royalty payment? When the video gets shown? What if it ends up on Putfile, do you get paid for every showing? What happens if it gets re-edited? Does your royalty reduce? What about if it gets dumped and never shown, you get nothing.

My advice is... if the band want a video they should find the money for it and pay you. If they had a gig but no transport they'd somehow find the money to rent a van.

Golden film adage "Any fool can work for nothing, and many a fool does."