First of all, it takes some time for a change in name servers to propagate across the internet. It's faster than it used to be but you still need to expect 12 to 48 hours for internet traffic to be rerouted. That means that the time it takes for the internet to know it needs to go to the host of your blog instead of Net sol can take one half of a day or more. And then, to change back to your original site/host would that about the same amount of time. That right there may be enough of an answer for you--without even addressing
SEO.
From an
SEO perspective, you've got more to loose than you have to win by following your strategy and since outages aren't typically for really long periods of time, you'd really just be spinning your wheels.
You could turn off your PPC when this happens. I don't know much about PPC on Nextag or Price Grabber and whether you can turn it off on the fly but you could if your were using Google Ad-words.