plug these into your calculator, or (better yet) find the nearest school kid to do it for you.
{(75,000 x 0.92) + (30,000 x 5)} divide by 5
then compare with 55,000
or try this
{(75,000 divide by 5) x 0.92} + 30,000
and compare with 55,000
essentially, IF you get all the tangible benefits stated all you save is the 8% discount on the original purchase or 8% of 25,000 per year. But you haven't yet factored in the costs involved with the change over and other change disruption add on.
In effect, you're messing everything up and making a lot of changes for a potentially possible saving of $2,000 per year if the benefits are realised. I doubt the change over will cost you less than $10,000 in staff disruption alone.
Hey and if anyone sees any problem with the above maths, don't mention it.