That's true but it's the way of the new world. The pros are that it would be lighter overall so it'll fly better. And even being lighter the Lipo pack will probably give you twice the motor run time so that means more flying or more flights on one charge.

The cons are that it'll cost more like you said but you'll have the motor, ESC, batteries and charger for the next E plane already.

And from a more practical point? You're running into the same thing I did a short time ago. They just don't sell that stuff any more.

If you're really serious about sticking with the old setup them PM me. I'll make you a screaming good deal on a big box of old can motors and gearboxes that I won't be using any more.