If your car doesn't have one currently, yes, it is worth it and will make a big difference in the way it feels.
If your car is a stock original that you want to keep that way, then that isn't a bad price for an n.o.s. unit. If your car is a resto mod and you want better performance out of it, a larger, aftermarket sway bar may be a better choice. Stock units are around 15/16 in diameter, whereas most aftermarket units can be picked up in 1" or 1 1/8". Firm Feel sells the most stock appearing bars with OEM style mounting points and hardware. You get these direct from Firm Feel as they do not have resellers. Other places like PST, Just Suspension, Blue Zombie, Mancini, Summit, and Jegs sell sell other units from Addco, Sway Away, Hotchkis and others that work just as well, but are far from stock appearing. in mounting and attachment methods.
Hotchkis recently came out with Mopar packages that contain a tubular 1 1/2" front bar and an adjustable 1" rear bar. Tubular bars are lighter than stock and the adjustable rear bar allows you to dial in the handling.