As for the price of diesel, yeah, lots of different factors to consider. I wish I'd bought my heating oil a couple of weeks earlier, before this latest round hit. Oh well. Can't time the markets.
I love that they're raising the prices on "premium" gas. The vast majority of cars (and boats) don't need it. I think it's more a prestige thing for most buyers. They like to pay more. It makes them feel good. If they want to subsidize my regular-grade fuel, I'm all for it!
My heating oil, which is basically the same as the diesel I buy for my boat, coasts quite a bit more than the diesel when the bill is examined closely:
22/09/08 656292 BIO HEAT 421.40 1.9590 825.52
656292 BC Carbon Tax 54.83
656292 ICE Fund Levy 3.31
656292 GST 44.03
The stated price of 1.9590 is slightly cheaper than the then current price at the fuel barge, but when you add in the carbon tax and ICE Fund levy, it boosts the home price by more than the cost of home delivery, by $ 0.1379 per litre. Then GST at both places.
As for premium gas, it is the only gas you can buy that has no ethanol, so whatever it costs, I will pay. I use it in all my small gas engines: home generator (which I have had to use three times this week), outboard (that sits with gas in it for the winter), power washer (also sits unused for months at a time) weed whacker, ride on mower (sits for the winter). cars (I have 3, so at all times there are one or two sitting unlicensed with gas in them. Ethanol "enhanced" fuels break down when left unused, so are not compatible with this usage case.
I also tried using regular gas in one of my cars at ~10% lower price and saw my average consumption according to the on board meter, and according to the cost of the next fill, go from 13.0l/100km to well over 15l/100km.
Here, the price for premium is consistently ~ 10% higher.
So the use of premium is not a matter of wanting to pay more for bragging rights. It is actually a choice to economize by using the fuel that gives the best results at the lowest cost.