With JLPCB 4 layers were and are the same price as two.? 5 off 100mm x 100mm come to ?9.45 including postage (not sure if this includes tax).
I think it might be worthwhile having JLPCB source and fit the attenuators, resistors and caps, SAW filters and Si4432 but as I don't plan on making another one just yet I have not fully investigated this.? I like soldering anyway (except maybe those attenuators!).
Dave