Honestly, if you can only spend $30-$50 for a buffer on your $35k+ rig, then just hold off and dont get one.
Dont go to the car wash either just because its winter.
What I used to do was to fill a 5gal bucket with warm water and car wash soap and bring it to the self serve wash places. Once there just use thier sprayer to wet and hose off the vehicle only. Use your own sponge and soap to clean. Now that I have a driveway, I just wait for warmer (warm enough so the water wont freeze

) weather.
Never, ever let the dealer wash your ride, even if, and probably especially if, its free.
I special ordered my 4R partially so as to get one that was never touched by the dealer. Told them not to do the initial dealer prep / wash process. And by not having it sit on the dealer lot for a few weeks/months avoided many daily scrub downs.
But back to your question the two buffers to get would be the Flex XC 3401 VRG or the Megs G110. Flex is a lot better but double the price. But even the megs is 3 times your $50 price.