Contingent on finding a new home?!

[Brandon Jackson]

My wife and I are looking at purchasing this house for ourselves. I was a little perplexed as to why such a wonderful house has stayed on the market for so long (almost 298 days). When we went and saw the house, we loved it. When I was speaking to the Realtor, he informed me that "all offers will be contingent on the owner buying a new house within 72 hours". I kinda had to pause for a minute.

Now as some of you know, Im fairly new to this. I have never run across something like this. I guess my questions are as follows:

1. Can someone explain this contingency to me? The Realtor wasnt much help. From what I can tell it means they will accept my offer if they can find a house for that price in 72 hours.

2. Is this normal?

3. Is it legal? Im assuming they would be using the funds from my purchase to fund the offer they make on another home, but Illinois is one of those states where almost everything can be illegal :)

I appreciate the help in advance