Well you are on the arduino forum so arduino!
Yes, the AVR butterfly is cheaper but there is a lot less support and example code. There are a lot of arduino 'clone' boards such as the seeduino boards which are pretty much the same but cheaper. You can always go with a stripboard arduino to really bring the price down.
Even an experienced programmer can have issues and need help every so often 
There are also libraries and example code for everything for the arduino.
Mowcius