If you decide on a 301, check ebay. The mocha ones are going for under $100. I don't know anything about the 206. Which bobbin configuration does it have? Vertical or horizontal? You want vertical if you can get it. A 301 will need a different FMQ foot because of the slant needle, so there's another $20.

Check E-bay and Craig's List. Facebook also has a marketplace.

The 206 is a vertical bobbin.

Funny story about the Necchi: I opened it up and it was clean inside, so I started oiling. I finally got it to move and I plugged it in and it did a few rotations and it froze up again. turned it manually and it unfroze. Pushed the pedel, and it turned a few times and froze. Repeat, repeat, repeat.... It was getting easier to get it to move past that stuck place, so i thought I was on the right path... Until I realized the motor was smoking when I pushed the pedel!! Unplugged and put on the shelf. It'll look really nice by the fire place mantle, don't you think?!??!

If the 206 is a vertical bobbin, then I'd play with it some more. Too bad about the Necchi. I've read that smoke is only old oil being burned off, but I personally would not take the chance. I love my few vintage machines, but I have to admit the old electrics scare me. I have a 1926 White I'm afraid to plug in. The 301's only problem has been the plug at the machine and a wall plug on the Universal acted up last week.

Check Craigslist or Ebay for used machines. That may help you stay within your budget and get a nicer machine.