It seems the most logical conclusion to state that prayer caused the difference. Any other explanation is less logical and more speculative.
What's the average length of time a home is on the market? 60 days? So on any given day the average home is probably going to have around a 1 in 60 chance of selling. A house that's been on the market for 2 years will, obviously, have a much lesser chance of selling on any given day. What do you think it is? 1 in 1000? One in 2000? One in 10,000? One in a million?
Again, 5 million homes are sold in the US every year.
Even if the odds of it selling THAT DAY were 1 in 10 million, that's still not really very improbable considering 5 million homes sold every year. What are the odds of hitting the powerball? One in 120 million? Yet people do it all the time, not only is there no need to bring in the supernatural to explain it happening, the statistics say that it HAS to happen. Just like with your house situation.
So, no, I'm sorry, but your conclusion is not logical. It completely ignores rational thought and any consideration of probability whatsoever.