There are so many different style in fashion. Therefore prices can change from garment to garment and all depends on  manufacturer's  finishes. It is hard to determine any price without seeing the garment.
Naturally there are standard alterations that can be blind priced .
                     PRICES        
 JEAN AND CASUAL LADIES AND MENS TOPSTITCH METHOD HEMMING: $ 5.50
If I have to open the bottom of the pants to be able to shorten them
+ $2.00

DRESSPANTS BLINDSTITCH METHOD: $ 7.50. If I have to open the bottom to be able to shorten them + $2.00

EUROHEM: $ 12.00

JEANS, KHAKIES, CARGO PANTS ZIPPER CHANGE:
$ 10.00

REGULAR ZIPPER CHANGE IN SKIRTS AND DRESSES:
From $ 10.00 - $ 30.00

INVISIBLE ZIPPER CHANGE:
From $ 12.00 - $ 35.00

MAKING BUTTON HOLES
One or First button hole $ 3.50. Additional button holes $1.25
FOR MORE AND ACCURATE PRICES PLEASE CONTACT/OR VISIT ME. 
   (Please go to "ask a question" page)
SKIRTS/DRESSES SHORTENING:
From  $ 12.00 - $30.00

LADIES JACKET SLEEVES: from $12.00 - $35.00

SIDE ALTERATIONS: from
$ 15.00 - $40.00.

SUIT JACKETS: Sleeves $25.00
S.J. Bottom shortenning: $ 20 - $30

ZIPPER CHANGE IN JACKETS:
$1.00/inch (I supply the zipper)

LEATHER ALTERATION: Prices will be higher.

ZIPPER CHANGE IN LEATHER JACKETS: $1.15/inch (I supply the zipper)

ANYTHING CUSTOM-MADE:
Starts from $ 30.00