Warranty would be covered by the company that you are buying from. It's probably a good idea to research them thoroughly. I guess you have some protection with Paypal and can file a dispute if the product isn't up to the description.
Yeah this is common for any prorduct we are buying from the real store or online e-commerce site. They will be give product and service warranty for the certain year.
If you want to buy the mining hardware or graphic cards. They mostly gives the 5 years warranty for that.
Check that whether they will send you including the shipping fee and customs. Mostly they asks you pay the high charge for custom clearance only.