Is it a no-brainer? I suppose it is if by that you mean the sort of purchase that someone with no brain might make. TCO is key when buying any printer. £38 for for a 1500 page toner cartridge, is pretty extortionate.
Also WTF is going on with your PPM calculations. The time it takes to warm up and print the first page, this doesn't count towards the sustained PPM count, the article said:
"Our five-page text print took 30 seconds, so a straight 10ppm, but when we increased the run to 20 pages, it completed in 1:24, a speed of 14.3ppm. This isn’t far off the spec"
14.3 pages per minute, isn't the maximum measured speed, it is the average speed. If it took 30 seconds for 5 pages and 84 seconds for 20 pages, it seems a reasonable guess that the last 15 pages of the 20 page run took 54 seconds - that works out at 3.6 seconds per page or 16.6 pages per minute.