Well, I found this Youtube video (recent, April of 2013) for the White 8000:
http://www.youtube.com/watch?v=mnTtojT9j44
To me it looks like an absolutely wonderful machine. I would pay $75 for it. If your budget for a new machine is $300, then you would still have $225 left in reserve for another machine if the White gives out. You never know how long a computerized machine will last; it could be 3 months, it could be 20 years. While you are sewing on the White you could simply save a dollar here and there to bring your SM kitty back up to $300 in case you need to replace the White down the line.
For me, it would be worth the $75 risk. You would definitely need to sit down and actually try the White before purchasing. Bring your own fabrics and thread, and make sure that some of the decorative stitch options you particularly want are working. You could also try offering $50 cash after trying out the machine, if you can bring yourself to do that.