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Why would you want to track only the transaction <$100 ?
Probably as an argument for or against micro payments. Payments over 100 USD are certainly not micro payments, thus an answer to the question could be an argument in a discussion.
I am curious too and am interested in the micro payment part of it. From comments above it would be difficult to determine the amounts.
Not really
#1 take prices from e.g. bitcoinaverage[1]
#2 start with block 1 (or any other you find more interesting, maybe Jan 2011) and itterate until you are at the current (or any other interesting, maybe Jan 2016) block
#3 determine day for blocktime
#4 calculate 100 USD bitcoin value for that day (you can also precalculate a btc value based on the pricelist in #1)
#5 itterate over all TX for the given block and filter for TX that match your criteria
[1]
https://api.bitcoinaverage.com/history/USD/per_day_all_time_history.csv