I used to work for an HVAC company in their IT department, ok I WAS their IT department. We had a contact for electrical wire supplies from a local lighting and electrical company. Their storefront was internal and external lighting as well a lamps, ceiling fans, etc. They kept bulk wiring of ALL kinds and you could just walk in the front door and buy UTP wire by the box. You may want to try to find a store like this locally and ask if they sell bulk wire. I remember it was pretty comparable to what online prices were. You would need a crimping tool and ends for the cable though.
Can I ask why you are using CAT7 cable? Cat7 uses GG45 terminating ends, which are backward compatible with RJ45 ports, but I don't know if there are even termination tools out there that are all that cheap. I guess you could terminate a Cat7 with an RJ45, but that's not in "spec".
Unless you are running 10GB 100meters you don't need Cat7. Cat6a will run 10GB 55meters and 1GB 100meters.