ARE there even any electronic/digital/computerized machines under $400, that are any good??
Look for a vintage Bernina 830 Record or a vintage Bernina 810/807 Minimatic on ebay, craigslist, local paper, thru you guild, or at a dealer where it might have been a trade-in. You can find them for $500 or less occasionally if you take your time to search.
They will have an extension table for a larger sewing surface, needle up/needle down capability with toe tap, 5 needle positions so you can get a scant 1/4" seam, and a carrying case. The vintage 830 also has the knee lift bar for hands-free raising of the presser foot.
Remember that 30 years ago this is ALL the machine we had to sew on! The necessary stitches are there, but you won't have decorative ones.
Can't even tell you how many delighted sewers I've turned on to these machines; I have 2 of my own and use them all the time!
Jan in VA