Here’s something we don’t see too often … nor will we likely ever see anything like it again.

Curtis Sleeper and his family have been building a one-of-kind 15,000 square foot home inside a cave in Festus, Mo., since 2003. However, he has recently listed his labor of love, which is situated on a scenic three-acre lot, on eBay.com for a thrifty starting bid of $300,000 because he no longer has the financial means to hold on to it.

Here is his reason for selling:

“We never considered an economic bomb to hit the country at the same time as our balloon note.”

That “balloon note” expires on May 1, 2009, which means that Sleeper and Co. now have 90 days or less to find a solution. Here are the options as he describes them:

1. Pay the previous land owners for the balance owed for the property, partially finance the purchase or investment in our property.
2. Sell our property and new house for as much as we can then pay off the balance owed for the property. Start a new adventure.
3. Hand over the property to the previous owners and lose 100 percent of our equity in the property and our total life savings.

The former sand mine is about as deep as a football field (100 yards) that has been split into three “chambers.” The front chamber is the living area with three bedrooms; the middle chamber is for storage and laundry facilities, as well as features a spare bathroom; and the third chamber is an open area with a stage where “Ted Nugent, Bob Seger, Ike and Tina Turner, the MC5 and many other bands performed.”

That’s because the “Cave House” used to be called “Cave Land” back in the day. It was once used as a concert venue, as well as a skate park.

Now it’s a house … for sale.

It’s a very interesting story that has captured major media attention recently for obvious reasons. To check out a video segment on ABCNews.com on the “Cave House” click here.

For more details on the amenities and all the blood, sweat and tears that went into building “Cave House” be sure to check out Sleeper’s very detailed Web site right here. And to check out the eBay listing go here.

Sleeper mentioned that he is close to securing the necessary $83,000 in financing needed to remain in the “Cave House” and is hopeful that his domestic spelunking “adventure” will continue.

We’ll pass along status updates on this situation as it unfolds.