I'm probably not going to buy it anyway - I am enjoying the extra space gained from selling my never-used surface grinder
The old quote is "You can make anything with a shaper, except a profit.".
Basically, it can do just about anything, but it won't do it quickly!
Internal bore features are a pretty neat use, if you find yourself wanting a keyway or spline, or even a square hole, it'll pay itself off quite quickly. Broaches are expensive
The ability to use single-point HSS tools is extremely useful. You can make some custom shapes that would otherwise requires a 5-axis CNC or a special cutter, like dovetails.
My favorite thing to do with it is actually just facing off material. I can set it to run, and go do something else on one of my other machines. This is REALLY useful! More importantly, I find it has a MUCH easier time (with just an HSS bit!) removing 'scale' or a tough outer layer than even my Carbide face mill.
Finally, the finish left by a nice shaper tool is miles ahead of anything short of surface grinding. Only a good fly cutter comes close, but with a more satisfying finish
Side note: I'm surprised you had a 'never used' surface grinder! I tend to use mine pretty often! The nice finish you can get on one definitely elevates any project!
EDIT: I'll also note that you can cut actually perfect involute gears on a shaper in a way that nothing other than really expensive cutters can do. And no, those sets-of-8 cannot do that except for 8 very specific TPIs, they work by approximating a center point in their range, a shaper can cut a gear tooth using the actual involute process, guaranteeing exact gears! It takes a bit of a setup, but at ~$50-100 for a decent gear cutter, you don't have to do too many of them before it pays itself off (if, like me, shop time is inexpensive compared to equipment costs).