mmm yea its hard to tell...
There were deals in which I saw good and quick profits. But there are cards that I have had for quite some time without being able to sell.
Still, I try to buy such cards that I know even if I get stuck with, they could be used by me. And the wisdom is to learn from mistakes too.
Do not do this if you feel unprepared yet, especially now that it is not yet clear which direction the DEC price will turn.
I'm definitely not prepared lol