I know what you mean. Our dealer here started charging $80.00 gal. and it wasn't even SeaDoo brand. I changed to Quick Silver PWC mineral oil earlier this year. If you make a change be sure to change to the same type, if you were using mineral oil you can change to Quick Silver Mineral oil, if you were using synthentic, stay with synthetic. You can go from mineral oil to synthetic but not from synthetic to mineral.
If possible you need to drain the old oil before changing brands. There is a whole bunch of threads on this forum about the procedure.
I changed from mineral to mineral, just different brands, so I drained the tank, changed the filter, put in the new oil, and bleed the lines.
Lou