i am not sure i`m understanding ur problem very well, however we`ll
try giving it a shot.

For the duplicates issue, and after u sort (or b4, wont realy matter),
try going to the leftmost empty column, and use the countif function

so, assuming ur table range is from A1 to E100, and that ur looking
for duplicates in the last name (which is Column B) for example, type
the following in F1

=countif($B$1:$B$100,B1)1

then drag (copy & Paste) the formula to cell F100

Now u`ll have (in column F) "TRUE" for duplicate names, and "FALSE"
for non-duplicated amounts.

then you can filter ur table (Data -- Filter -- Autofilter) --
Please make sure to use the filter on the column headings row (Name,
Last name, etc..)

Please inform me if it works or not.