you can build a sentienl swarm deck the only rares you need

are *4-longshot and *4-underground base

the only thing that is hard to get are the mark4s

You can build Arkham Inmates with pretty much entirely commons, plus its fun to play. If you can find anyone selling commons in bulk, or any card shop that features a 10 cent bin for commons, this deck should be dirt cheap.

4x Harley Quinn
4x Two-Face
4x Puppet Master
4x Charaxes
3x Man Bat
4x The Joker, LL
4x Killer Croc
2x Mr. Freeze
2x Bane

4x Fear and Confusion
4x Nasty Surprise
4x Finishing Move
4x Flying Kick
4x Crushing Blow
4x Combat Reflexes
3x Acrobatic Dodge

4x No Man's Land

I'm pretty sure all of the above cards are common
With this deck, mulligan aggressively into charaxes, and try to keep most of their men off the field...have fun with cool powers like two-face, puppetmaster, and Joker

Then, you can add some uncommons
-Kidnapping
-Ratcatcher/Query and Echo
-Prison Break
-Overload

Finally, if you want to fit in a few rares
-Poison Ivy

There you go...budget inmates control. :)

Thnaks I might try that one out. Also a LOA deck might be worth looking at.