Buying Buying an Existing Lien on Property I'm Interested In

For per personal reasons I am interested in buying a specific piece of property. The property currently has three judgment liens (Fieri Facias) on it. The liens are all associated with credit card debt of a previous owner and nominally total up to about $15,000. The original credit card debt was bought by an attorney (presumably for pennies on the dollar). And, that attorney subsequently got the judgment liens. The owner is reluctant to agree to a price because he does not know how much he will really walk away with if these liens are settled in the real estate closing. He currently has the property rented with a break-even cash flow and does not need to sell it. I feel that if we let the attorney holding the liens know that there is interest in buying the property he will stick fast to the judgement amount; hoping to get that in the closing. I am considering attempting to buy the liens from the attorney before entering any negotiation with the property owner. That would give me a new bargaining chip. Does anyone know if this is a viable approach and how to go about it? What would be a reasonable cost for me to buy the liens outright, not satisfy the liens? To me it seems like an offer of pennies on the dollar should be adequate because they would still be liens, and of no value to anyone except me unless they can be collected on. This is in Georgia.
CORRECTION FROM THE ORIGINAL POST: I may be using the wrong terminology when I said “buy the lien.” Probably the correct terminology is “buy the judgment.” What I want is the legal right to collect (or otherwise make use of) the judgment as I see fit, including agreeing not to collect it if that helps the negotiation.