You can pick up a mini cut off saw from Habor Freight for $20 plus shipping.

http://www.harborfreight.com/cpi/cta...emnumber=42307


Edit.
When you do start cutting your arrows dont be like most of the shops.
First cut a inch or so off the nock end then install the nock and cut to lenght.
That way you are going to be using the straightest section of the shaft.

Most shops will only cut them to lenght so if there is any run out wobble in the nock end that arrow is trash cause you aint gonna get it to fly straight.