Here are the Märklin USA price lists we have on file. If you can fill in the gaps please send mail to me using the address at the bottom of the page.
If there's an image in the far left column you can click on it to download the price list as a PDF file.
In addition to the list above whose contents were transcribed, here is a PDF of an Item Master list dated April 15, 1994 which appears to have prices for "everything" including every parts, layouts, promotions and other dealer-only items.
April 15, 1994 Item Master (4.7MB)