My LHS also does the lion proglow blended syn for about $10 a liter as well.
this price was for there blended oil 25% castor 75% klotz (or similar)
my home brew 5/20/75 mix costs me $2.96AUD a liter if i go to a synthetic oil with castor it'll bump up the price to $4.11AUD a liter.
Sooo cost wise may be i'll stick with my current brew untill i find a reason not to.
when you look at this price and consider the LHS is buying the ingrediance for a LOT less $$ than me it makes comercial or LHS blended fuels a bit of a rip off
also has any one tried the Shell racing M, it's the Shell version of the Castrol M BUT the Shell product is 35% synthetic, it's about $9.50 for a liter and $40 for a 5 liter, i've just ordered some to see how it goes