The total monetary value from the 80% of 40,000 contributors is somewhere south of $3.2MM (I say "south" because it is $100 or less), and the balance of his $14MM haul (which is $10.8MM) came from contributions over $100.01.
So a little math shows us that the size of the average donation of the balance ($10.8MM / 8000 donors) is $1350.00.