Ok, here we go with the great Ross myth again. Only one model, the M-10 or MkIII, (those are the civilian and military model numbers respectively) was capable of the bolt being installed incorrectly and thus being dangerous.
There is a huge variation in models and prices. If your Ross is a sporterized military rifle it will fall in the $100-$200 range. A military rifle in complete original configuration can be in the $800-$1200 range. One of the rarer civilian models could be worth even more. Bore condition, finish, condition of woodwork all have a bearing on the price. It's sort of like saying "I've got this car for sale, it's got four tires and an air conditioner. What's it worth?"
I would suggest looking on the canadiangunnutz.com forums under milsurps and do a search on Ross. There are several very informative threads there. Someone who regularly visits there posts under the name Rossguy. He is probably the foremost Ross collector in North America, is very willing to share info and knowledge and is a great guy to deal with.
If it's military it's in .303. If it's civilian it could be 280 Ross, a hard cartridge to get, or any of several other chamberings which were offered.
If you email me I'll be glad to help you figure out which one you've got.
45-70, If you're afraid of yours, send me some pictures and I might be interested in giving it a new home.