miller/docs6/docs/data/dollar-sign.txt

$ cat sample.csv
EventOccurred,EventType,Description,Status,PaymentType,NameonAccount,TransactionNumber,Amount
10/1/2015,Charged Back,Reason: Authorization Revoked By Customer,Disputed,Checking,John,1,$230.36
10/1/2015,Charged Back,Reason: Authorization Revoked By Customer,Disputed,Checking,Fred,2,$32.25
10/1/2015,Charged Back,Reason: Customer Advises Not Authorized,Disputed,Checking,Bob,3,$39.02
10/1/2015,Charged Back,Reason: Authorization Revoked By Customer,Disputed,Checking,Alice,4,$57.54
10/1/2015,Charged Back,Reason: Authorization Revoked By Customer,Disputed,Checking,Jungle,5,$230.36
10/1/2015,Charged Back,Reason: Payment Stopped,Disputed,Checking,Joe,6,$281.96
10/2/2015,Charged Back,Reason: Customer Advises Not Authorized,Disputed,Checking,Joseph,7,$188.19
10/2/2015,Charged Back,Reason: Customer Advises Not Authorized,Disputed,Checking,Joseph,8,$188.19
10/2/2015,Charged Back,Reason: Payment Stopped,Disputed,Checking,Anthony,9,$250.00

$ mlr --icsv --opprint cat sample.csv 
EventOccurred EventType    Description                               Status   PaymentType NameonAccount TransactionNumber Amount
10/1/2015     Charged Back Reason: Authorization Revoked By Customer Disputed Checking    John          1                 $230.36
10/1/2015     Charged Back Reason: Authorization Revoked By Customer Disputed Checking    Fred          2                 $32.25
10/1/2015     Charged Back Reason: Customer Advises Not Authorized   Disputed Checking    Bob           3                 $39.02
10/1/2015     Charged Back Reason: Authorization Revoked By Customer Disputed Checking    Alice         4                 $57.54
10/1/2015     Charged Back Reason: Authorization Revoked By Customer Disputed Checking    Jungle        5                 $230.36
10/1/2015     Charged Back Reason: Payment Stopped                   Disputed Checking    Joe           6                 $281.96
10/2/2015     Charged Back Reason: Customer Advises Not Authorized   Disputed Checking    Joseph        7                 $188.19
10/2/2015     Charged Back Reason: Customer Advises Not Authorized   Disputed Checking    Joseph        8                 $188.19
10/2/2015     Charged Back Reason: Payment Stopped                   Disputed Checking    Anthony       9                 $250.00

$ mlr --csv put '$Amount = sub(string($Amount), "\$", "")' then stats1 -a sum -f Amount sample.csv
Amount_sum
1497.870000

$ mlr --csv --ofmt '%.2lf' put '$Amount = sub(string($Amount), "\$", "")' then stats1 -a sum -f Amount sample.csv
Amount_sum
1497.87