Is it all brand new stuff, never run or flown, or is it a used plane/engine/etc someone wants to get rid of? If any of it's used, the price sounds high.

If it's all new, and you know who assembled it and trust their work; it depends which OS engine and which Futaba servos are included. Here are two extreme examples using 'standard' servos.

ARF 130 at Horizon
Servos 70 S3003, $10.99 each at Servocity
Engine 70 46LA at Tower Hobbies
Total 277

ARF 130 at Horizon
Servos 140 S3001, $19.99 each at Servocity
Engine 130 46FX at Tower Hobbies
Total 400

If everything's bottom of the scale, is it worth $123 (to you) for someone else to assemble it? If it's all at the top, you get the labor free