A mechanic told me a leak was a result of an inner axle seal that needed to be replaced but when I took it to my mechanic he said I needed the seal and a new axle. I read that axles seldom need replacing. What do you think?

I understand. The reason I question it is that 2 mechanics disagree. The first one, who couldn't do the work, said during his inspection, he didn't see any damage to the axle. The second mechanic when asked said it had no oil in it, probably meant grease. But the first mechanic said there are 2 rubber boots that hold grease on the axle and they were fine so the axle must be fine.

IF the axle SEAL is leaking - transaxle fluid is what would be leaking out - therefore at some point more fluid would need to be added back to the transaxle. IF we knew exactly what is leaking we could provide more assistance.

I was told it is the front passenger side, inner axle seal that is leaking

That is a possibility I guess however it is not something that normally occurs according to the posted mileage on your vehicle.. But then again - I cannot inspect the vehicle myself.. Good luck with it!