I would love to order everything from Amazon, and not have to deal with all the potential Lazada/Shopee/Ali hassles I read about.
In addition:
1) Amazon cs is excellent;
2) Minimally I can get 5% off but usually or often more than that;
3) Unlike all the phony 3rd party vendors I read about on Lazada et al, the Amazon 3rd parties will try to do anything to please the customer (and hence not get a bad review);
4) Lots of user reviews of the items for sale.
However:
a) Many things I want can't be shipped to Thailand (or possibly in some cases the 3rd party sellers don't want to), e.g. Vitamins., Soap.
But I will try using iHerb for Vitamins which (almost?) everyone seems to be happy with;
b) Shipping fees:
They do have a flat rate $9.95 USD to Thailand,
and currently about 4 mostly very small lightweight items which I want to order can all be combined under that single $9.95 charge for all.
I don't know at what point they cut off a combination of items under that single charge.
But for the items which they do allow to be shipped to Thailand, many of them are shipped from the 3rd party sellers, so do not come under the flat rate $9.95, and the shipping fees can double or more the price of items.