I purchased badge holders and luggage straps from Amazon. (I like going thru Amazon as I feel I have some recourse should anything go wrong with the small vendors.) There are several sellers that offer both - you save on shipping that way. I used the following two products:
1. Advantus 75451 Proximity Badge Holders - Vertical, 2-3/8x3-3/8, clear. They come 50 to a pack.
2. Sparco Plastic Straps for Luggage Tags - SPR01160. They come 100 to a box.
I found 4 sellers that sold both, and with shipping here was the cost:
1. Plex Supply - $28.82
2. Shoplet - $29.45
3. My Office Source - $30.53
4. The Factory Depot - $33.19
You have to do some poking around to find them - but if you use the searches "Proximity Badge Holder" (be sure to buy the verticals ones) and "Plastic Straps for Luggage Tags", you'll find the products, then just click the "12 available new/used from..." link and it will bring you to the sellers.
Here are what the straps and holders look like empty:
And here are the inserts I made - I just used leftover cardstock from my boarding passes:
I found that running a letter opener across the holders made it much easier to put the inserts in without bending the corners.
I've included the template for the inserts. I left the goofy "luggage tag" around the outside edge because it's FI's favorite part - it's in the Maiandra GD font, and the little trees are in Tropicana BV. If you don't have both they are on DaFont.com, but they will help you see better.
Print them double sided - at least on my printer, they line up perfectly.
PS - if you did the math, then you recognize that I've got a bunch of the loops leftover - for the sake of my late RSVP-ers, assume I've got 30. If you want them, they are yours for the cost of shipping. PM me if you want them.