I'd probably try to save it if it's a Singer Queen Anne cabinet with all the parts. Not too hard to find a Singer machine for a cabinet like that and, as someone else mentioned, it can always go back on the curb in a year if it doesn't work out for you. (All this said by someone who has never successfully finished any kind of refinishing job on furniture!)
Regarding the World Rotary machine in cabinet, I would add that if it's a working treadle it is well worth $5! My bet is that it is not a treadle, though.