RE: rtf or building
I let my students learn to fly with my own trainer and gear then if they plan on sticking with the hobby then to go out and buy there own radio and gear. I see too many people give it a try then decide it isn't for them so other then fuel they aren't out anything using my stuff.
ARF or RTF is the better way to go for a first plane, maybe even a second plane, the second plane seems to really take the beating.
Some RTF combos are really a pretty good deal if the club doesn't have an instructor with his own trainer set up.
Get into the hobby as cheap as you can and see how you like it.