im a frequent buyer from shopee, lazada & aliexpress for stuff from china.

shopee, cheapest + shipping, shipping took 1 week plus.
lazada, less cheap than shopee but faster shipping at 1 week.
aliexpress, more expensive than shopee & lazada but more variety , shipping at least took 3-4 week on aliexpress standard shipping.

from a buyer perspective, cheap price including shipping beats all unless wana urgent then local seller win but with higher prices. im also consider local seller if the item has probability to be held at custom.