Any quality difference in Speedometer cables?

So my speedo has not worked in the 10 years I've owned my dart.

Today I decided to see what the problem is.
Well theres about 3"-4" section of the cable that was laying across the exhaust pipe at some point in the past, the plastic is all melted off, the cable housing is cracked and rusted. Cant turn the cable at all.

Spent 1-1/2 hours searching my garage, cause I swore I had one from a 71 scamp that was in usable condition. Well, it has vanished of course.

So looking at new ones on ebay, the prices seem to range from $15.99 (generic) to $75.99 for one that says Mopar on the package.

Any real difference in these? I cant really see paying $75 bucks for a speedo cable, but I do want to get it working.

p.s. anyone know the correct length for a 68 Dart cable, some for sale say 68", and some of the generic ones are 80"