Good news: I found another source for the Sony MDR-7506 head bands for those who would like to build up another pair of headphones without having to squander the headband and gimbals from a pair of Grados. The source? The Sony Support center in North America. Also, their prices almost knocked me out of the chair this morning. About $9.00 for the headset and $2.50 for shipping. Yes. $11.50 total for the lil' beast shipped within the U.S.
Bad News: It looks like I bought the last one. I wanted to order more, but they didn't have anymore stock and they ran searches against other warehouses, to no avail. Plus, it wasn't apparent that more would be placed back into stock, so it's hard to tell if we'll see any more again or not from Sony. Also, I did a check for the MDR-7502, which also fits the Grado cups, or custom wooden cups, and has been used by Chris Langely with success. However, that was out of stock, and not sign of more to come in. Finally, after digging a bit more, it looks like the older MDR-7504 has a band similar to the 7506 and is a replacement, too. However, the MDR-7504 is a bit rare due to age as it looks to have been a product 12-15 years back.
I still think others who are looking for a lesser cost alternative for a headband and gimbals, should check with Sony Support if they are in other countries outside of the U.S. When I called the support number, I listened to the menu options and chose the one for purchasing Sony accessories. Here in the U.S., the number I used to call was: 239-768-7691, and was published on one of their Web sites.