I know it sounds weird but if you have a King Soopers Marketplace (the larger stores that have a full toy section) check there. The one up north...
Wally World on 10th in Greeley has Siege Starscream and Soundwave as of this morning.
When I went I didn't expect to see them after reading your post. It was a pleasant surprise. :)
Target off of 47th and HW34 had a Shockwave and still has a Ultra Magnus. They also got in the voyagers and have three of Optimus and Megatron....
Wal-Mart on 10th and 47th as of Tuesday had Overlord in the clearance aisle. I think the price was $30 but don't hold me to that.
I have seen Shockwave at the 23rd Ave Wal-Mart and Target in Greeley.
I bought both sets from your ebay store! Can't wait.
Separate names with a comma.