Well, I went to my local TRU and found Armada PL Prime on sale for $20, so I snagged him...I already had Jetfire...now all I need is Overload/UM. I know Energon UM was an extremely limited run, so does anyone have any tips on where I should look to find one (other than eBay)? Any help is very much appreciated.

I'd say keep checking the TRUs, they seem to be trying to clean out some of the old Armada stock. I'm debating whether to pick up Armada Tidal Wave for $15. Wal-Mart doesn't seem to hold onto older stuff as long. You also might try Kay-Bee, though the one near my house had nearly no Transformers ever in stock. It's closed now. Coincidence...?

I concur with Goldfinger, I've seen quite a bit of Armada lately at TRU. My guess is there was quite a bit of Armada stock left sitting in the warehouses while TRU began preferentially shipping Energon. I've specifically seen Overload within the past month, so I'd keep an eye out for more to hopefully show up.

 

Wal-mart and Target seem to have already releived themselves of leftover Armada, I wouldn't bother checking either of those places for Overload or Ultra Magnus.

Target has been a popular place to find Energon Ultra Magnus, but these sightings are few and far between, and at this point, Target or eBay are the best bets for Ultra Magnus.