As for whether you should be using them: Many still do recommend selling them but my personal advice is that it's no longer a strategy worth bothering with, before their nerf it was actually decently balanced, they made a good amount of cash but nothing insane and it did box you into a very specific gameplay loop that took time later to break out of (and build up skills/progress elsewhere).
Now the sell price doesn't really make it at all practical, and the limits it imposes on your playing isn't really worth the cost, you're better off using other methods for making cash like fishing which was buffed a fair bit in 1.6, even in the early game