[Leica] Leica batteries

[bob catchpole]

Hello again,
How much are folks paying for their rechargeable Leica batteries? 

'Official' M9/M-E batteries are available online for £89 (http://theclassiccamera.com/epages/BT0261.sf/en_GB/?ObjectID=1277764) or $129 (http://www.bhphotovideo.com/c/product/461931-REG/Leica_14464_Rechargeable_Lithium_Ion_Battery_f.html), while 3rd party versions are a fraction of the price.
What do people advise? In your experience do "you get what you pay for" or are the cheaper versions ok?
Thanks,Bob