It's tough to say how busy we'll be. Which is why I'm hesitant on getting just one machine for printing / cutting. Right now we manufacture custom buttons and we currently produce around 400,000 buttons a month. I don't see a problem with turning some huge business quickly doing decals / custom stickers. Do you think it would be wise to get a separate printer and cutter system?
If you want to print get a printer. If you want to cut, get a cutter. A machine that does both should automatically be suspect as doing one or the other, or both, poorly.
A Shopsmith comes to mind as the epitome of this sort of machine. At one time I thought that this was the machine of my dreams so I sold all my stand alone machines and bought one. It certainly did everything, but none of it well, and I spent far more time setting it up as this or that machine than I did actually using it. After a few month of putting up with this I sold it and bought stand alone stationary machines once again. Now when I need a band saw, I step over to my band saw. When I need a table saw, I ease over to my table saw. Likewise drill press, joiner/planer, shaper, belt sander, disk sander, spindle sander, lathe, etc. Each of these tools are basic transportation, nothing fancy, but each and every one of them out performs the same function on the Shopsmith and is orders of magnitude handier. That was 30 years ago and I still have the same tools all fully functional.
Regardless of that, the vast majority of the time you remove the print from the machine, do something with it or to it. From lamination to just letting it sit there. Then at some later time you load it into a cutter and cut it. On this basis alone separate machines make a lot more sense than one machine.
It has been noted that with two machines you can have both going simultaneously. In my experience this happens but not all that often.
The one telling objection to having it all in one machine is that when, not if but when, it needs fixing, you're pretty much out of business until it's back on the air.
All in all there will be many apologists for a single multi purpose machine. Ask how many of them converted to that from separate machines. Then ask anyone who went from a single machine to separate machines if they would ever go back.
The only compelling reason for a single machine is space. For that to be a valid criteria you must be operating out of a broom closet. The foot print of a plotter is about that of a couple of chairs.