if you read the comments like this, the whole problem is that the items cost Koban and do not reflect!
the mystical things are simply too expensive and since a lot of people don't have that much money to top up Koban regularly because they simply don't have the money or the prices are too expensive.
Because one thing is certain if you want to play well you have to invest about 30 to 100 or more real money to make good progress, the objects then of course take the place for the players who do not simply have the necessary change to afford something or do it together to save.
It's really hard to save too many Koban on the test server.
if the mythical items would cost just like all other simple mirrors (with the exception of the boosters) many would surely welcome that.