Akron Ohio: Abandoned Property with Tax Lien Certificate

[Ronda R.]

There is a house I am interested in that is right next door to my sister-in-laws rental. In talking to the neighbors it has been abandoned for several years. I looked into the deed on the county site and found that there was a tax certificate that was purchased on it in 2011 for $3,566.00 at 11.75%. I have never heard of purchasing tax liens until now and so started reading about it here. Further research showed the owner and wife have both passed away. Property still shows the deceased as the owner though I imagine it should belong to his children.
I would love advise on how to pursue purchasing this property. Would you contact the lien holder and make an offer (but they don't own it yet) or the children and make an offer. Can they then redeem the certificate?
Would love your input. I would not want to pay more than $15,000 for it in the condition it is in. She purchased hers for $22,000 rehabbed.