Unique Tax Lien Situation in Colorado

[Ethan Au Green]

Can a tax lien certificate holder use the lien as leverage to negotiate a favorable lease-to-own agreement with the owner?

I'm pursuing this kind of an opportunity in rural Colorado. The tax lien was recently sold on a 50 acre farm with several thousand mature fruit trees plus greenhouses, open fields and water rights. The residential buildings are all in shambles, but the farm itself is worth saving. Because the county has a random bidding process and sells the face value of the tax lien rather than auctioning it to the highest bidder, I was not able to bid on this property's tax lien. But I'm in touch with the holder of the tax lien certificate, who said he'll probably want to sell it to me for a small premium. 

After I get the tax lien certificate, I think I'll be in a great position to negotiate lease-to-own with the owner, who is in financial distress, has mental disabilities and no competency managing a productive farm, and honestly needs to get out of the situation for her own health and sanity. Is there anything legally or ethically to prevent me from acting on this plan? I'm not trying to rip off the owner or do anything unethical, I just want to use possession of the tax lien certificate as a foot in the door to seize control and save this gem of a farm before it completely goes under. I do have abundant experience in sustainable agriculture but I'm completely new to real estate investing and tax liens.