Ditto… Chargers and packs vary wildly in cost.

As for charger, you can get a real simple charging module for under $50, a decent charger with readout for about $100, and some nicer high end chargers for $200+. The kicker here is if you have three packs, and want two on charge, one in plane, you need to buy two chargers, or get a dual output version.

Battery cost depends on capacity, number of cells, cell type, etc. In my case, a pack for a F3A 2M pattern ship was going to run between $700-$1,100 per pack. This may sound silly high, but I spend about $800/year now on glow fuel for ~400 flights, so I can almost make it work, but just not quite yet. But, a 30" wing span plane could easily be fine with a $50 or under pack. So it really depends on what size of plane, or more precisely the motor current and desired runtime, as to which pack is needed and the cost.

I'm not convinced electric is cheaper than glow on small planes under 40 sized. I think that the total cost is low enough that it doesn't matter a whole lot if they are 20% more or whatever. But I'll admit I've never looked into that size real close.

Cheers.