Honestly I am in the same boat as you are I am a beginner, but I would go with a vintage machine instead of a new plastic throw away machine. A lot of the vintage machines can be had for under $125 and you can still find parts for them at your local dealer or eBay. Plus they are low maintenance and they will last you forever!
My recommendation would be a 301 Singer, they are portable full size machines that only weigh a few more ounces that the Feather Weight 221 or 222K and you can pick them up on CL, eBay and local thrift stores. I have seen most go for under a hundred bucks around this part of the country and they are plentiful.
Its like this why spend $500 on something you think you might or might not like, and if you do find you love to quilt like I do then if you want a fancy machine then go for it.
Billy