...I would agree w/ Christopher. If I have an
average day with an average guide giving an average effort(you'll know it if you experience it)I would be hard pressed to even go 10%...so I wouldn't assume a minimum.
I had great experience with a guide last weekend. Fishing was tough and we worked for every hook up we got...but he stayed right there with me...
End of the day the float cost me $200...I tipped him $40...and for his efforts I thought that was fair. Go with your gut, you'll know whats right.

Brookid