1 sheet of stinger costs around 2k~2.5k depending on the shop. The other option is to open the car door, drive around and figure out what component is causing the rattling. tighten the screws and see if that helps. you still need to ensure this even if you are applying sound deadener ( which btw reduces the metal rattling and not the window motor, lock actuator etc from rattling). You need to ensure all the etectrical components are securely tightened to the inner door sheet. you can stuff jumbolon foam inbetween the components and door sheet to be on the safe side.
When you are applying sound deadening sheets, make sure you cut holes to reveal the bolts that hold the electrical components so you can tighten these in the future. These sheets are a one time application only, you can remove them in the first few hours after application but after a day or two, these become permanent. Removing them becomes a PITA and you will only end up with ruining the deadening sheet. The only way to remove these will be to cut them. So you have to make sure what area's you cover.
If you dont wanna go bonkers with the deadening, you need only cover 50% of each surface to help ensure the metal from flexing/rattling. Thus one sheet of roadkill is enough to cover both the inner and outer skins of the front door with over 50% coverage on each side.