buying online u render the risk that the product is not as expected, and u need to pay extra attention to the terms & condition (usually some bad seller would put in small font or wadeva)
while buying from simlim shops u can check the product and bargain before paying.
pls noted that not everything on the e-shop is cheaper.
anyway, it depends on urslef.
if u think the transaction is secure and there's some kinda refund guarentee, u can buy from e-shop; or else, better not do e-shopping.
ps. ebay is quite good, i've been using it for quite a while.