I did little research on both the varieties. I had similar doubts like you. But the ground rule is same for both. Each will give you an approx Rs 200 to 250 Max per plant. Here are what people do near my farm.
Go for Yellakki Bale and not the puttabale that grows in Malnad. Both are different variety. Yellaki bale at you farm gate fetches around 25 to 30 Rs depending on the season. So the yield is approx 8 to 14 kgs max. Do your maths. But the plus point is the bulbs are available cheap costing Rs 1 or 2 where as
G9 you need to get TC plants. Govt cost is Rs 8 and pvt is Rs 10 to 12. Transportation extra. Here each plant yields a min of 30 Kg and to some lucky ones a Max of 75 KGs. Price is Rs 4 to 7 Max /KG. Again do your maths.
Advantage of G9 is it is resistant to some known deadly disease, where as yellaki bale if one gets it, it spreads to all.
Dont go for puttablae which grows in malnad, they look like yellaki but not. Best it is used in “Sringeri Banana Chipps”.
I have the hand out of Govt horti for banana. else for TC visit Jain.com they have a online pdf for G9.