If you can get your money back is up to the seller. This doesn't sound like it's at some resale shop that offers a 7-day guarantee.
If you're asking: "If I buy this for $50, could I sell it for $50 (+cost of rear wheel)"
If everything is in good condition and you have a used rear wheel, probably. A new wheel, tire, tube, freewheel, derailleur/cable/shifter/housing (if it was SingleSpeed and you're restoring it) could cost upwards of $200 for cheap stuff. No way you can sell it for $250.
If you have used parts in good shape, in many areas you could sell the bike for $100-$150 as a complete, ready-to-ride bike. Sold as is right now? Difficult to find someone like yourself willing to buy a bike without a rear wheel at nearly any price.
If this is the Gran Sport I'm thinking of, it is an all-Reynolds 531 frame with some really nice components on it. As long as the frame was not Drewed, I would buy it for that price even if the seat and stem were stuck, just on the glimmer of the possibility of freeing them.
Wheels are expensive purchased new for sure, but buying a parts bike would be a very inexpensive alternative. (E.g., I just bought 2 complete bikes with good quality wheel sets for $20.)
If it were restored to near original with a correct rear wheel replacement, I'd venture to say it could provide you with a very handsome profit were you to sell it.
Well i went and looked at it a bit better, It has rust spots and looks to be pretty decent but the paint is pretty worn a little to worn for me, also the decals are pretty much shot. I also noted that nothing on the bike is original it is a mix of parts. It was also a 73 model Honestly to much work for me right now i have other projects that i can work on.
Im sure it is worth the fifty bucks to someone but not for me.
The Gran Sport is a very nice Carlton made 531 Raleigh with a Carlton fork... they are a beautiful riding sport class bike. On that basis I'd say a frame and fork that were in nice condition are probably worth 50.00 to the right person.
Bought mine for it's frame, fork, GB stem, and bars (and paid $10.00 at a thrift store) and it has been one of my favourite bikes for many years and has lived life as an ss, fixed gear, geared road bike, and now it is a fixed gear again.
My paint was faded and the decals were also in pretty bad shape but after a little work she is looking a lot better than she did and now hits the curb at about 19.5 pounds.