I think you need to differentiate a little. If you look for any branded item either Taobao, Alibaba or Aliexpress will disappoint you. Not just for LV or Gucci stuff, also expect brands such as Kingston etc. to be fake.
I rarely use Alibaba, and wouldn't use it for consumer products, but I use sometimes Taobao for some RC and electronics stuff. I have a friend a Shenzhen buy it for me, but I plan to get Alipay and then want to order from Hong Kong, with delivery to HK. I bought a few well over RMB1000 items there and so far no bad luck.
There is Yahoo Actions in HK, but their product range is maybe 0.01% of that on Taobao.