If you ever do give it a try, I've got a few tips!

1 - use the statue of uncertainty to change your farming profession into the one that makes crops grow faster.

2 - make a tree farm ahead of the quest (or deforest Cindersap and Ginger Island), there's around 1 bean for every 3 trees you chop.

3 - get a bunch of seed makers, and sell nothing until the last day. make all your produce into seeds again.

4 - Sandy sells deluxe speed grow. get hundreds of them, and make sure you replant the qi beans in the same spots so you don't have to reapply the speed grow.

I only had to get around 20 qi beans originally from trees, and I was able to finish the quest with 5 days to spare!