I don't know how long it will last, but Amazon (UK and Europe delivery only I think) are currently selling the 2 top Hi-MD units at ridiculously low prices:
Sony MZ-NH1: £109.99
Sony MZ-NH900: £69.99
3 weeks ago when I checked last, these prices were £219.99 and £159.99 respectively. So if you are thinking of one of these, I don't think you'll get a better price for a new one.