The A70 has more storage, a better camera, a larger battery, more memory, more RAM, runs a newer version of the Android OS, Supports VoLTE calling, has a larger screen and is cheaper than the S8 was. 

The A50 and the A70 are similar devices, but the A70 has more memory and RAM than the A50, but it is also larger and more like the S8+ than the S8 in size.

The A70 is only $150 on Corporate, so with a $150 hardware discount, it would be zero. The A50 is already zero.