HSI is probably your best bet for future expansion/reduction.
LE has cheap and abundant low denoms but $25s on up are impossible now that I think about it. I'm not too familiar with IG pricing but off the top of my head it sounds very doable, especially since people seem to be moving on from them already.
Some more recent TCR sales come to mind like IG and LE or some slightly older much more available sets like HSI or HSCleveland. So bottom line sounds like about a Paulson 1000 chip cash set for $1-3/chip average.
