I have gone both ways in 30cc. 2 seasons ago all I had were 30cc electrics, mainly 8s setups. I invested in the generator, power supplies, chargers, etc. As the gas engine options improved, I started to try gasser setups for the longer flights times. At this point all I have up and running are gasser setups with 2x VVRC 40 twins and 2x OS GT33s. I am going to get a electric setup later in the season as I am fascinated by the options in 12s as I have a ton of 6s 3300s for my 60" laser. Also I just invested in a cargo trailer that will have the charging setup in it, so my opinion might start to sway back to electrics, as my major issue with them is all the toting around of the massive charging setup.
I think the actual flight experience is superior with electric. Light weight, instant torque, and bigger props, all add up to a wonderful 3D experience. The gasser is more grab and go. Just need to charge the RX packs and fuel it up, flip, and fly.
Cost wise, IF you consider batteries fuel, then the electric is much cheaper. One less servo, the motor and ESC will add up around $250, versus $400 to $550 for the gas engine, standoffs, fuel tank, IBEC, tubing, filters. Also the gasser takes much longer to setup installing all this stuff.
Generally, my electric 30cc planes have come in around 10 pounds AUW, while my gassers seem to average 11.5. This is with at least 4 data points on each type of setup.