They are only cheapest if you remove the cost of converting the designs between 2000 <> 2002 as this is also 'hidden' time and money
As far as I know the upgrade price is not so expensive, I would ask them to change one copy to 2002 for your own work and if they do not upgrade then take the work to another company.
Cheap is not always good, cheap also needs some volume work to stay cheap and profitable, so your work might be very important to them, more than they tell.
:R