I am ready to pay for turbo delux which is $40 but it says $80 I did not us the state. How do I pay the $40 only?

Here's how to remove the state forms in the Online software, so you are not charged for them.

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-delete-my-state-return-in-turbotax-online/00/25895

Just be sure you really don't have to file in MO. 

Age 65 folks in MO get additional deduction amounts, but that doesn't mean they don't have to file at all, unless their income falls below a certain level;

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"  You do not have to file a Missouri return if you are not required
to file a federal return.

If you are required to file a federal return,
you may not have to file a Missouri return if you:
a. are a resident and have less than $1,200 of Missouri adjusted gross income;
b. are a nonresident with less than $600 of Missouri income; or
c. have Missouri adjusted gross income less than the amount of your standard deduction for your filing status"

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Of course, I have no idea what income  sources you have..so it's not something I can tell you...just make certain you know for sure you don't have to file MO.