Is bike fit really needed? I'm having neck pains and muscle cramps when I go for long rides (> 90kms) . I don't know if the reason is due to big kms or is it the fit of the bike.
I live in India where a bike fit costs 12000 INR($195).
Do you suggest me to get a bike fit compulsorily ??

Thanks.
If you are having pain and riding a lot of volume, it makes sense to get a fitting. Your other options are to


continue to experience the pain, possibly doing long term damage to your health. 
reduce your volume of riding
get a different style bicycle with a more relaxed and upright geometry. Your fitter may recommend this anyways.