If you are using the same zip code to calculate shipping charges as you are shipping from, you may be running into an issue with the overlapping expected delivery dates.
When multiple delivery services have the same estimated delivery date, eBay will hide the more expensive options. This tends to be most apparent when the buyer is closer to the seller (or the seller searches the seller's own listings). The farther away the buyer is located, the more likely the more expensive options are to actually appear. eBay apparently thinks this makes things easier for buyers, though many would prefer to have the options available even when there is no estimated difference in delivery dates.
I opened one of your listings and only saw the free delivery option. But when I changed my shipping zip code to 90210, the expedited option was shown.
