Glade Riders disappeared in the purge as they switched over to AoS. A lot of things were lost- more than I can easily list- but the basic rule of thumb is that anything which required a slottabase is gone from Fantasy.
Basically, in the switch to round bases anything which had tabs on the feet would no longer fit the new bases, so they were dropped.
They're a pain in the butt to find because it all happened with no warning- many popular things suddenly went to 'last chance to buy' on the website, causing a bit of panic buying, and it was all gone within hours. Overall it was a poorly handled s#!t-show, as the timezone differences and website updates meant that many places sold out and then brought from other countries, causing them to sell out before anyone there even knew what was happening. Website updates also didn't keep up with the stock losses, so many people's orders had to be refunded and things people thought they had secured were suddenly lost to them.
About a week later they did a brief production run of many, but not all, popular things to try and please the customers, but it suffered the exact same problems and was overall a very limited stock volume- here in Australia we hardly saw any stock return to sale, despite all the promises.
eBay prices skyrocketed for quite a while, and many people still try and charge an arm and a leg for previously common units.
Your best bet now is to join every second-hand site you can, or scout out shops that are likely to be clinging to old stock and who have few customers.
