A YS engine is by far the most expensive glow engine out there. You can get a super tigre 3250 for like $250, or an OS 160 for 300. Now there is bang for your buck if you know how to take care of them. I am not sure if your using YS as an example has to do with pattern flying as I don't have much experience there. Just making a point. Electrics are more expensive but the longer your plane lasts the closer it gets to even. As I said before in my experience it took about 300-350 flights to make the cost equal. That is a lot of flying. And a bottle of glow fuel, may cause damage if spilled, but it does not light on fire and destroy your $450,000 camper or van. That is what concerns me most about EP. I do not have the experience or mentor to teach me safe operation of lipo. I would probably be done flying if I caused that kind of damage to anything.

Edit: 450,000 can buy you a LOT of glow fuel. That is also a large price to pay for convienance.