Not even sure what the term over-pay might mean

My take is that "over-pay" means that they may pay more than what "25%" is worth as an "insurance premium" to make sure the rest of the 75% they get for pennies on the dollar are not going to be in jepordy because of the other 25%.

It's like buying a house, with 25% of the house (say the basement) owned by tenants that you don't want, so you offer to buy the basement from them at more than what it's worth. Say the whole house is worth $100, 000 which would mean that the basement is worth say, $25,000 - but you pay $35,000 to get them to move because you're getting the rest of the house for $50,000 (in effect, paying $85,000 for a $100,000 house). Completly arbitrary number's, but to hopefully illustrate an idea.