Very low cost for better than Sentinel-2 is hard.

If 3m is OK then you could look into PlanetScope imagery, although getting small amounts as a hobbyist might be a pain.

I had a look at SkyFi, and there is some 75cm imagery in Aniak that you could buy for 20 bucks (for 5km^2). I doubt you can do better than that.

Tasking VHR imagery can be costly, as there is usually a large minimum order size. For archival, you just have to hope someone else took a picture of what you are interested in.