They were clearing out Pennzoil Premium Plus Synthetic Blend at the local Wal-Mart last week. $5.75/gallon. My Polaris likes it.
I usually buy a jug or two of the Quicksilver for my Merc during the BPS spring sale. $10 is my spending limit for, ehem, "high end" oil. Yes, peace of mind is worth a little more, but not twice or three times the price.
Mike, I probably wouldn't chance low-end oil in an Optimax either, since it runs a very thin margin for lubrication error. But lots of folks have blown up an Optimax while feeding it $20/gallon oil.
I figure it works something like this:
You buy a $6 jug of Exxon TCW3, you are getting about $4 worth of product, and about $2 worth of marketing and profit margin.
You buy a $16 jug of Quicksilver, you are getting about $5 worth of product, and about $11 worth of marketing and profit margin. Yes, there are additional ingredients in the mix, and it costs a little more to manufacture, but mostly, Mercury (and Yamaha, and Bombardier) have you by the psychological short-ones and they know it.