From having a 4x4 Sprinter, and having spent a lot of time driving Grenadiers, if your needs are fulfilled by one of those two vehicles, the other one will not be well suited for it.
For instance, both the Sprinter and the Grenadier can tackle a good bit of terrain (our Sprinter has upsized tires, not lifted but completely upgraded suspension, full skid plates, hi-lift compatible sliders, and a winch/recovery points), however, the Grenadier is MUCH more capable (more ground clearance, shorter wheelbase, better angles, MUCH more capable 4x4 system assuming you have F/R lockers).
Both are great for daily driving, however the Grenadier is much easier to navigate around car parks, into parking spaces, and you at least have a chance to fit into garages. I have used the Sprinter as my daily driver for almost 18 months, and while it is doable, it isn't the most ideal situation.
Now when it comes to trips and travel, the Sprinter affords us with 24/7 climate controlled space (heat and AC), induction cooktop, 20 gal (76L) of water, a toilet, super comfortable bed; all accessible by literally turning around from the front seats; and while the Grenadier is undoubtedly less cumbersome to drive at 85MPH (137KPH) with a 30mph (48KPH) crosswind than the Sprinter (and it has absurdly comfortable seats for hours of drive time), it cannot offer us the comforts of home at any time like the Sprinter can.
I'm not sure of the global Sprinter pricing, but if it is anything like the US, a Sprinter configured for long travels will be significantly more than a Grenadier