BiggerPockets

I had a transaction where the property had the deed distributed and one of the people who had a 1/8 interest in the property IRS liens. It took 3 lawyers and a large national bank 60 days to gat a release from the IRS for a partial distribution instead of the net proceeds.
They don't like to give up what they have and it's easier for them to let the time run out than send a legal release.

Like a bank, the IRS doesn't want acquire the property and will generally release it early unless there is substantial equity. Not sure what their threshold is, but repairing and marketing the property is going to cost the IRS a good bit more than it would cost an investor (due to the red tape inherent in any government activity). I believe there would have to be at least 25k or possibly much more equity for them to redeem.

File form OBD-225 - Application for Release of Right of Redemption in Respect to Federal Tax Leins. It will cost $50, but could knock a month or three off the redemption period. Don't do any work before the 120 period is over or the property is released -- unless you're feeling particularly charitable towards the IRS.