The information from Crossy is spot on.
I ordered about 2 dozen things from china within the last 12 month for my house (to be built). I do not want to go into detail here, just my conclusion for you:
1. usually, VAT and custom duty is added and has to be paid by you. Custom duty varies (on the kind of good), but the total can be 30 to 50 % of the original buying cost (it is also due on shipping cost). Handling customs can be a nightmare and has to be skipped by letting the task to the seller
2. shipping cost is not cheap, unless you fill up a whole container
3. I would only order again when I can agree on a DDP order with the seller, meaning all duty, tax and shipping cost is paid by the seller, so included in the total price you get from the seller. But that means that the seller is able and willing to do his homework on this and offer you a DDP price.
4. Avoid things that have to be build in, like windows, doors, a kitchen. too many things can go wrong. Well possible are sofas, chairs, sculptures, beds, lamps