This is what I did ...
I found a $80 marked-down display model, from wallymart about 4-5(?) years ago; it was around $299 retail to start with (& up to $399 at some stores, still today) ...
When I bought it, I asked for the box & noted that all the attachments & Info sheets were still inside it.

They had it hid under their fabric table for quite awhile, so it had been marked done in the computer SEVERAL TIMES, it was marked $180, but a quick scan showed it would ring up at $80.
Being a display model, of course people & children had spun all the tension dials & fiddled with all the parts ... so, when I got it home, I spent about 2 hours reading the manual & resetting the tensions (don't let that scare you. It takes me 1-2 minutes NOW, that I know how it's done right.) ... And It's been just wonderful ever since!

...
I clean it out with an air compressor after every other outfit and I've oiled it once or twice. ... I pre-cut most of my fabric (*roller-blade addict*), hence I don't use the serger's blades very often = so, they are still sharp, after all this time. ... I change the needles every once in awhile, since I work with alot of denim ...
+ I put that rubbery-shelf liner stuff under it, so that it does not run around the table when I'm using at full trottle.

I love it ... it's a Brother 1034D
Alot of the Wallymarts are remodeling = I'd check around the fabric tables, to see if there's a serger they aren't displaying anymore, ask if it's marked down and if they still have it's box & contents

... And IF you aren't up to fiddling with it to get it up-to-par again, perhaps check local sewing machine shops, to see what they charge for tune-ups

... You could save a couple hundred dollars, if you time it right. ... AND remember, keep your receipt & box, since Wallymart has a 90 days return policy, just in case.
You could use
pricegrabber.com ... IF you're looking online.
I've had great machine luck & customer service with
sewvacdirect.com, with 3 machines & tons of other things

I saw a NEW ONE at
buy.com
I walked by another, newer model at one of my wallymarts lately (now-ex-display-model), but didn't see a price tag = if you want me to, I can ask them about it for you ...
GOOD LUCK!