I don't think it's uncommon to have gearbox issues with them. Mine is often difficult to get into reverse - lifting the clutch foot a little seems to work.
Quite common to find first difficult when cold. Some solve it by using thinner gearbox oil. Hopefully just an issue with the linkage which should be fairly cheap compared to something in the box itself.
Ouch! That's a crazy price. It wouldn't surprise me if a good independent could do it for a lot less. It also wouldn't surprise me if the original cables could be reconnected, unless of course one has snapped.