There is actually a true a la carte streaming option where I live. My ISP
(Spectrum) offers two different TV streaming options:
1. For $25/mo for the first 24 months (no contract) I can get the following channels (no a la carte picking and choosing): ABC, CBS, FOX, NBC, AMC, FXX, FXM, HGTV, SyFy, Lifetime, Disney, Disney Jr, Disney XD, Nickelodeon, Cartoon Network, TNT, TBS, TruTV, Discovery, Animal Planet, BBC America, Comedy Central, Freeform, TLC, Bravo, Oxygen, USA, Hallmark, National Geographic, CMT, History, A&E, Food Network, TCM.
-OR- choose option 2 below which is really a la carte
2. For $25/mo for the first 24 months I can pick 10 channels, in addition to having five local channels.
That second option is probably exactly what you're looking for. However, you have to be a Spectrum internet customer. I'm not sure if you have Spectrum in your area.