Why would it "cost" you money to park $200k at Bask where you get 1 mile per dollar on deposit, vice parking that same amount at any other bank where you will get something like .2 cents ($.002) per dollar on deposit? If you don't value an AA mile at more than $.002 than you probably aren't much of a frequent flier, so the whole point is moot.
What are the miles "valued at" for IRS income tax purposes.
Also as a secondary issue ,It is very easy to get 60 to 75 basis points
or about 400% more than your comparison.
Using 20 basis points for the example is justifying "giving use of your capital for AA Elite status".