I just went thru this myself.
Wanting a smaller, lightweight machine for classes & retreats.
I looked @ new but couldn't stomach paying a new price.
I, too, wanted to be in a less than $300 price bracket.
Bought my Viking D1 new 7 yrs. ago & it works for me beautifully,
so I set out to find a 2nd machine in used, but excellent condition.
Found one! They are out there.
You can check craigslist, eBay, quilting & sewing forums, etc.
I was very very leery about buying off eBay but the seller was 2 hours from my home,
she had good reviews, & she said the machine was in pristine, like new condition ... only used 5 times.
So I took the plunge.
I couldn't be happier! It looks & sews like it hadn't been used more than 5 times.
This is less than a classroom model.
I have the Viking Prelude 360.
I paid $195 for it. It originally sold for $450-500 depending on the area.
I've been sewing on this machine to make sure that I like it (& I do) ... so am going to spend a
little more now & order a sewing table top for it. I should still come in @ less than $300.
My 2nd go-to choice was one of the Baby Locks, but the one I wanted was $599 + tax.
Nice thing about used ... generally no tax.
Good luck on your hunt.