I suspect you are correct, but I'm still curious to see if anything comes close to ether. I've been able to find tables with characteristics of various light distillates. Is flash point the correct datum to use for comparison?

While searching for the tables I ran across a report that says that over 450,000 kg of ether is produced every year in the US. Ignoring "controlled substance issues," my guess is that I wouldn't have a bit of trouble buying it if I was willing to order it by the barrel. I know firsthand that this is true for castor. I found a supplier locally who had a price of USD $1.67 per pound (.45 kg) for AA castor. All I had to do was order 440 pounds (198kg)!

So, all I need to do is either find 200 diesel flying friends to split the costs or figure out some alternatives.