Dell Docking stations are practically free, yes. Even on Windows, I've had issues, because of the Dell fuckery with docking stations - single cable docking doesn't work if your docking station is too new, and your laptop too old. Bananas.

On Ubuntu, I've purchased 3 different docking stations, and tried 2 existing ones, and none has worked quite right (some just flat out don't have all the drivers they need). The Windows laptop I have (which is extremely similar in hardware and generation), if you get a video signal out to a monitor, it's a very safe bet everything else works.

Back to "Practically Free" for old Dell docking stations. I acquired 3 of them for about 15-20 each shipped off eBay. lol At least I'm not sinking hundreds of dollars into each attempt at a docking station that may or may not work.