buy just the hand or fix?
There are two hands listed as 'buy now' on Ebay for $14 ~ $16. That's less than the kit, but you would get more spare parts for your money in the Cabella's kit.
There is a June 29th post by maillemaker, on a thread about 'a bent ear on an 1851 Colt Pietta', that shows what the hand ( number 7) looks like on the Colt. The hand/spring assembly looks similer on the Remington. Basically a chunk of steel with a flat spring in a slot.
I would first disassemble it to be sure what you've got. Maybe your spring just came out of the hand slot and can be reinserted and peened or soldered in place as mentioned. Watch for a small flat piece when you take it apart. Try to use as little heat as necessary if you solder.
If the spring is broken, then you might as well try Hawg's fix before needing to possibly fit a new hand. Remember part of the 'fun' is making it your own. As has been said here before, these pistols are just kits.
And I would not throw the old part away, but would save it for a pattern to fit the replacement hand, or just keep it to fix as a spare if you get a replacment hand.
You also may want to try to figure out if you did anything to break the spring ( if it's broken), to keep it from happening again. There are several things that will stress the hand spring, like turning the cylinder backwards.
When you get more than one BP revolver you will need to poly bag your junkbox parts so you can mark and remember which parts are for which pistol.