Re: lubes
Yes. There are differences between oil made for water cooled outboards (TC-W3) and other, non-TC-W3, oils, made for air cooled 2 stroke engines. The differences aren't great and some oils say they are suitable for both.
Use only TC-W3 rated oils in water cooled outboards.
Prices are all over the map. The differences in price are generally a reflection of how much the seller spends on advertising, marketing and promotion.
It is my opinion that price is not an indicator of quality in outboard oils. I have used Wal Mart's SuperTech for years with zero oil-related troubles.
One exception is synthetic and synthetic blend oils. They usually make less smoke, pollution and carbon but cost a lot more than petro-oils.