o not a silly question at all! New they go for $80.00 but if you use one of the 15% off codes you can drop it down to $68. 00. I use it after i clean my rims to remove all water from hard to reach areas (lug nuts, barrels) and I find it to be very useful. i have been debating the master blaster. But Im not sure I want to spend $400.00 on it lol. It would be super cool to get it. I Also use mine for all cracks, headlights, engine bay after i clean it. So probably outside. I haven't really used it on the inside. I bet it would work well for blowing dust out and other stuff. I also use mine to dry out polishing pads too. It is very strong.
https://adamspolishes.com/shop/accessories/brushes/adam-s-blaster-sidekick.html