i have finally finished making caves into little "grids" by my house so that the crimson/hallow won't spread.

(click on image for a better view)
this took 8 hours total (a little rough estimate, i play on and off)
and ~20 plat for the solutions. i havent finished cleansing all of it, only about 40% of it. (and that took 6 plat)after cleansing just 4 of the grids, it took around 4 plat, so its def. going to be higher than 30