Aliexpress is fine for certain things. But that pricing thing is silly, it's just to spoof the algorithm (it's awful anyway) and to generate clicks. There will be an UNO seatpost for $17 or something like that, and some will have it as $16.72 with free shipping, others will go for $11.89 with $5.23 shipping, and then there will be guys who will advertise the seatpost for $3.56. When you click on it, you will see it's $3.56 for two Ti saddle bolts and $17.67 for the seatpost. It's a mild annoyance and I always go to one of the guys selling for $16.72 with free shipping, because they haven't wasted my time, however mildly.