Mostly our "premium" tournaments are 5 credits entry for the custom course and top 10 pays out. AFAIK that's as cheap as we can do it (I don't set the tourneys as lucky to be able to leave that to a very good man who runs all that).
We might sometimes have another near as daft as to how much can be won by any individual. Within reason, any member or above can set something up and have done so.
I would say just play what you enjoy. I would forget all about averages and stats and just worry about your own score history to track your improvement if that is what you are looking for- JMHO.
EDIT: I already veered away from the original question - Eloquently answered by Alosso. Perhaps I should add (realising away from any OP point) our ethos on generally low as possible entry fees and seldom even then is simple. My experience says people fall out quickly as soon as winning meaningful credits get put on the line. Any prizes that do get put up are meant as fun as generally come out of the time our tourney director puts in earning them by watching vids etc..........My own "earnings" have just about covered me for ball costs and the odd club upgrade ( I am fine with that). My credits come from me edge feeding in low stake RGs / Brackets (prem WGT tourneys).
Some clubs will offer more credit tourneys ( I guess mostly for those not good enough for RGs etc). Some will do it well I must assume and some look crap holes:).........Our belief is that if work is put in we can get you good enough for open tier comps WGT wide, and that's what we stick with as we have a good track record on that happening (for those that care to do that - some in the club could but simply don't care to and that's fine).