This is a very good investment in my opinion. However, I really like this item and sadly it will be very hard to get rid of this item for me. Looking at the graph, for the past couple of weeks it has been very up and down. The max that it seemed to peek was around 35k. So when you see this item drop below 35, be sure to pick it up and then wait till it peaks back at 35 which it seems to do every so ofter. Previously I've seen this at 50k but right now it seems to be capped at 35.
Right now it is 35k so today would not be a good day to buy it as you would lose nor gain any gold. If you do however, want it or yourself, buying it at its cap price could end up in a loss if the market decides to not like mythrill armor. Yet I doubt this would ever happen.