Good pattern/cutting layout software? Sewing Machines Parts and Sales in Los Angeles

I’ve been making patterns out of graph paper by hand, but it would be nice to be able to play with things a bit, print out multiple copies, and especially to be able to mess around with different cutting layouts to figure out what’s most efficient. I don’t necessarily need “here are my measurements, make me a dress pattern”, since ATM I’m mostly doing accessories and I’m fine with defining the shape of each piece on my own, but being able to automatically add seam allowances would be awesome.

OS is either Windows or Linux, and while free is always nice, I’m willing to pay decent money for a good program.