RTSmovers typically have the part that you need. However, they can be higher priced than other parts. AutoHaus for example specializes in selling Mercedes Benz OEM parts.
Euro Parts offers quality replacement components at an affordable price. They are therefore an excellent choice if want to keep up with your vehicle on a tight budget. They don’t list the source of their products. Buying an aftermarket blower fan is an option since it’s cheaper. But, it can help you reduce your expenditure on crucial parts that may affect your engine and the other moving parts.
Phoebe Parts, another manufacturer of top quality replacement parts can be found. They manufacture their components in China, but their pricing is generally much lower than buying from Mercedes or any other place.
There are other trusted brands to provide high quality parts. What you should examine is the country of origin. For example, parts manufactured in US will have a higher standards than products produced in China, Vietnam, or Taiwan.