I recently found a NIS (but very dusty) copy of Märklin at a LGS. We liked the variant but hated the tiny merchandise tokens. I replaced them with 19mm x 6mm wooden disks from Print Play Games. I made up stickers using the template available on their website.
They're a little pricey, but a big improvement over the fiddly stock tokens. It would have been cheaper to go with 15mm x 4mm disks but I'm happy with the larger size.