I will include a surprisingly well-written instruction sheet, but rebuilding a board is at least mildly complicated, and you should know what you're doing and have a decent soldering iron. This kit may not fix your Marantz if it has other issues, but it will definitely help it run better, and should fix most phono board problems.
US shipping and handling is $7, and international is $21, no matter what quantity you buy. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. If you have any questions, please ask.