... But this will be an ongoing and recurring project, possibly as often as a couple of times a week, occasionally a couple of times a day. Using a camera would mean a setup of the "easel" or whatever holds the document, the lights, and the camera on a tripod. Then fiddling with memory cards for the upload.
On the other hand, my current scanner is several years old- and was used when I got it- and needless to say, I've used it a lot. So this is a case of killing two birds with one stone- not only get a scanner big enough to do the large job, but also replace- or just augment- the existing scanner, before it dies.
Now, had the only large-formats been $1,700 and up, yeah, I'd go with the camera. Hell, I could buy a used XT just for this job and be money ahead at that price.