I think the best way to inhibit fake dayi is not to value real dayi more than its real value. But probably this won't happen anytime soon
I think what's going on now is something a Malaysia businessman shared with me many years back, "拉高打低" concept. Creating an upmarket with high prices, then hit the market with stuffs that you really want to clear.
If a new popular DY cake cost 600RMB, then a 06-08 costing 500RMB would look like a steal