Workshop costs vs. Orders on the Interne

What makes buying spare parts or to buy used cars online on the Internet so attractive are above all the low-priced alternatives and comparison offers - especially for original parts in OEM quality. Whether in a Mercedes, Renault or Audi shop, the Internet offers the best comparisons with the best quality for brands of all kinds. The always cheapest market prices can be compared very easily here. If you compare the ordering process with repairs in a workshop, the mostly exaggerated costs for working hours are eliminated. Of course, you have to have some know-how when installing various auto parts, but to be honest, instructions and video tutorials are now abundant in the vastness of the World Wide Web. What do you think?