This may not be what you want to hear.... but if you are concerned with the cost of glow plugs you can more than make up for it with the cost of fuel.

I buy 15% nitro synthetic oil fuel form my LHS for about $18 per gallon. I run this straight in my Saitos.

For my OS, Enya and TT two stokes I cut the LHS fuel 50/50 with 0% fuel that I make myself.

To make the 0% fuel I buy methanol from a local speed shop for $15 for a 5 gallon drum. I buy castor by the gallon from Sig or S&W for $16 per gallon. I mix them up by volume 4 parts of methanol with one part of castor.

The result is a 7.5% nitro castor/synthetic blend. The 2-strokes love it. Really pretty easy, and saves me about 6 dollars per gallon on the 2-stroke fuel.