Two Janome sergers are on sale, one White is regular price at Hancock Fabrics www.hancockfabrics.com
They are all available online & at the stores.
$159 White 1634
$199 Janome 3434D (regularly $329)
$279 Janome 9102D (regularly $349) ,similar to 3434D but has the easier threading method - $29 more than your budget