I own a Canon imageCLASS MF-726Cdw. It doesn't get much use here @ the house, but, it has been trouble-free. I purchased an imageCLASS MF-733Cdw for my church. It backs up a Kyocera TASKalfa 2552ci which is leased. It sees minor usage. Outside of having difficulty checking for firmware updates, and, provided documentation that is sorely lacking, the 733 has been well behaved.
Canon's imageCLASS devices are similar in appearance and specs to units sold under the HP logo. I suspect that they are all produced by a common third party.
1000 copies/month may be nearing the ceiling for the imageCLASS line. The current top models (743, 745 & 746) do have high capacity toner cartridges available that might make more financial sense than the standard cartridges.
Would purchasing a refurbished all in one machine be doable...say something along the lines of the imageRUNNER ADVANCE C3530i III? Yes...the initial outlay would be high, but there would be no contract limits on how many copies could be made.