I just hope they don't have "levels" of paid accounts based on followers for example. A single $20-$50 per year would make sense to me. But I imagine whichever route they choose, and no matter what cost, they'll sell anyway.
I think the key part of it is the "verified" part of the deal.
#1 rule of startup pricing: CHARGE MORE.
Exactly. There's no reason why the paid twitter business accounts should be priced at the $20/mo. level. Maybe for verification alone that makes sense, but twitter could easily charge $100/mo. or more.
0 - 999= $9/mo 1k-10k = $29/mo 10-20k = $39/mo 21-30k = $49/mo 31k-50k = $59/mo 51k-100k = $79/mo 100.01k-300k = $129/mo 300.01k-1mm = $259/mo
For the value that Twitter Business Accounts will provide to businesses, a basic fee of hundred of dollars per month sounds reasonable, and then added features could cost extra. I know I would pay if I were a Dell or a JetBlue.