$600 is definitely on the high side to get started. I usually recommend $400 to $450, including a 40 size ARF trainer, engine, 4 channel radio gear, and field equipment. (Including self contained starter and glow igniter.)

Trainer ARF = $100
Good engine = $90
Radio Equip. = $120
Starter = $70
Pump = $15
Glow Igniter = $25
10% Fuel = $15
Misc. = $15

Total $450

BUT! You can get a used trainer, often with engine and radio for $150 to $200, or the newer RTF's are going for $250 on sale (with engine and radio).

Heck, last week at a local auction I bought a used 25 Size Right Flyer (trainer), with an OS25 engine, all servos, battery pack and a 6 channel Futaba radio for $60! It's in pretty good shape, some scuffed up covering, but no real damage, and the batteries were all charged ready to go.

I'll fly it a couple times, use it for demo flights when kids show up at the field, and eventually sell it to one of them for what I paid. Can't beat the smiles that will bring with a stick!
Dennis-