Not all copier vendors can offer 3 Tier pricing. Besides the built in technology, a significant investment must be made in the back end accounting system to handle these extra line items on the invoice. Furthermore, via service code it is possible to vary what that the toner coverage thresholds are making the entire process rather arbitrary and very hard to certify.
I would suggest that you be a little cautious if the successful vendor asks you to install proprietary software on your network to collect these meters and automatically report them. This same software will likely sense your entire network and report considerable detail on all your network print devices. Automatic meter read reporting via email is OK as it reveals only specific network information on the copiers your plan to install.
Plus throw in some free color copies.
When the competitor offers the customer apples change the proposal and offer the customer potatoes! Be different and do not go down the road the competitor is leading the customer on.