Yes, the economic benefits would be astronomical.
No, asteroid mining is nothing but mere sci-fi, and it is way too impractical with modern tech.
This would be beneficial in multiple different ways. The only thing I would fear is the over mining of asteroids as they do serve a significant purpose in our solar system.
By itself, it might not be economically feasible, but if combined with exploration to be done anyway, could be worthwhile. And especially if done on asteroids demonstrated to have a chance of collision with earth, provided they have means to prevent accidentally altering it's course so that it would.
We could continue some funding.
Imagine the cargo space you would need to gain profit.
Though I love the concept, with modern day tech it is a bit impractical. Right now we are in the exploration phase when it comes to space travel. Collecting resources will come once we finish that and make a realistic way of doing it.
Not now, invest in advancing space travel and exploration first.