The cheapest legit source should be this authorized dealer of Lexar in Beijing
http://dtshuma2008.taobao.com
Only 399 RMB / 66 bucks for 128GB
http://item.taobao.com/item.htm?id=19079387814
Other than that, Komputerbay is selling one for $110 through Amazon
http://www.amazon.com/Komputerbay-128GB-Professional-Compact-Extreme/dp/B008O7N0W6
It ain't getting much better unless we hunt for deals off eBay or wait for something like Black Friday etc.
Sometimes there might be some insane deals posted @ FatWallet / TechBargains etc. but they might involve rebates and such.
Heck, I might wanna take the plunge and get this Lexar 256GB for 1,500 RMB ($250 or a dollar per GB) after Chinese New Year since they're also claiming to be another authorized dealer
http://item.taobao.com/item.htm?id=19070224289
The question is can we order this 256GB from Taobao to UK? At £150 is a great price. I hope it will work with Mini and Video ipods.