Automatic gearbox

[GINGERNUT]

Hello everyone. Can anyone help please. I have a 1998 GLx Estate which has developed a leak from the automatic gearbox/shaft . Noticed when we started getting small drops of grease/oil on our drive. first thought it was a leaking seal, but my mechanic tells me that there is too much movement for it to be just the seal. He discovered this when he started to replace, and decided to hold off until he could get some idea of cost for a repair or replacement ,and whether or not I should just get rid of the car.
Can anyone advise what sort of movement would be acceptable - my mechanic is talking "big time" !!!

any ideas would be appreciated

Thanks

[mjb]

All depends what's up. Seals are probably cheap, and a pair of driveshafts will set you back £150. A new gearbox/diff will cost a fortune, but can be picked up fairly cheaply at breakers yards/ebay