Although I strongly recommend purchasing sewing machines from a local reputable dealer, many people shop online. Here you'll find links to price comparison for purchasing serger machines online.
Equipped with an automatic looper threader and built-in roll hemming and capable of differential feed to gather fabric for ruffles and reduce stretching when sewing knits, this 4/3/2 thread serger can perform numerous stitch functions while stitching, trimming, and overcasting in a single operation. It's simple to operate, fast , and uses standard sewing-machine needles. Stitch functions available include 3-thread and 4-thread overlocks. Price: $264.99
Adjustable differential feed permits serging on contemporary fabrics Automatic looper threader; built-in roll hemming with fingertip controls 1300 stitches per minute; color-coded threading guide; easy tension adjustment Adjustable stitch width and length; free-arm conversion; accessory storage Soft carrying case and illustrated instruction and how-to booklets included. Price: $259.99