I recommend you PayPal to pay your purchase in a secure way.
Check the seller's reputation. Most web sites post feedback rating of sellers based on comments by the others buyers and sellers.
You should also remember that you may have to pay for shipping costs, customs duty, VAT, etc. All these hidden costs will push up the price, so it's good to make a shopping list before and buy all things at the same time.
Check whether the company has a privacy statement that tells you what it will do with your personal information.
Be sure to print a copy order confirmation for your purchase and also save any email receipts.
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