Many of the replacement parts are very competitive from Mercedes and one should always compare prices with them. Ebay parts are in most case higher priced since the sellers know that most buyers assume the original parts are more expensive. I just compared the price of 2 fuel hoses and the seller on Ebay wanted $128.00 plus shipping and the exact same parts from MB are $38.00! DO YOUR HOMEWORK PEOPLE!!!
That's a bit of a generalization, I think.
MB is generally competitive on parts where there are multiple sources--
but not always. Multiple sources include, of course, either 3rd party parts, or reproduction parts or similar. So, fuel lines and hoses? They may be competitive on some of these. However, you can get factory-rebuilt starters and alternators from MB, in the gray box, and you can get the same from a number of Bosch authorized resellers in the yellow box. As you say, compare prices...MB in the past, has been
considerably higher on those electrical parts. So high as to be, at the time I checked, "not competitive".
There are multiple vendors for things like water pumps, and many suspension parts, and of course it pays to do your homework on quality as well as price. Some years ago, a lower control arm grease cap (small rubber piece) was torn on my car. It was not sold separately from MB, and moreover, because MB didn't want you to replace this one at a time, the lower control arm "kit" to do it was sold in pairs. To officially get that grease cap, I would have had to buy
two control arm kits, to the tune of
many hundreds of dollars. Miller's sold me a reproduction grease cap, just one, for $4.95. Of course, a lot of suspension parts on the W113 were used in considerably larger quantities on sedans, so a thriving market developed for aftermarket parts.
On proprietary parts, (think some trim, grill star, etc.) MB can be alarmingly costly. I think a grill star is in excess of USD $1,200 now--but short of a used one, or NOS that someone wants to dump, they are your only source. If it were not for the trademark issue, it would be reproduced by others and the cost would be out of the stratosphere and somewhat more down to earth.
We have a good list of vendors here, in the USA there's K&K, Millers, Bud's that deal in parts, and some of the other places (SL Tech, Black Forest) can help with some parts in addition to service. There are many online parts sellers, such as AutohauzAZ. Internationally, Dan Caron, SLS have great reputations. I personally only go to eBay for an obscure used part not available elsewhere; there are just too many good people out there serving this community with good reputations, and that's the first choice.
As you say, do your homework...which is why I sometimes cringe when I need a part, knowing I've got a lot of homework ahead of me...
