Those people are very short-sighted. It is great to see they are willing to pay that much for pinyin names. I will not let my IDNs go cheaper.
It is an easy decision for sedo, follow the market. We should not expect auction houses to promote IDNs for us.
Actually, those pinyin names can be considered as "typo" of the IDN names. They will get some natural traffic if the corresponding IDN names are developed and popular. On the other hand, if the pinyin names are developed, that will help the IDN names even more.