pump replacement?

[TractorTech]

thought it was a bit spendy for a used pump which might be 90% wore out

You were asking for a replacement shaft for your pump and that is not how it's done. This pump may be worn out, meaning the housing is worn out, but the gearset may work in your pump. I would think that is not the case and you could ask the seller or counteroffer at half the price.