Swingwing
This is a very interesting question, and as an "older" fixed-wing pilot who has always fancied himself as a chopper pilot after few hours "cattle spotting" for helimustering I will be interested to read the responses.
Let me state up front that I don't know much about helicopter training, but in true PPRuNE fashion I will not let that stop me from having an opinion.
I know 2 blokes who, being over 50 and with no previous aviation experience, decided to learn to fly a chopper. It took both of them two Robbies each to achieve their PPL(H). Both pranged one early on in their training.
I reckon if you are only going to fly a chopper, why bother with the fixed-wing, focus on learning to fly the chopper. Someone headed down this track should not be worrying about trying to save a few $ by getting a fixed-wing PPL first.
Choice of chopper for both training and subsequently might also be an issue. There appears to be a bit of a cloud forming over Robbies, or at least their rotors.
I know of at least one guy who bought a Jetranger and learnt to fly in the machine he intended to operate. He didn't seems to have any problems and I have read that that is a good way to go if you have the coin.
Dr