I would be very careful regarding using an expired domain if you are going to be using it for your main website.
If you are going to be buying expired domains with existing backlinks and traffic for your private blog network, that's one thing.
However, if you're looking to use an expired name for your main website that may be cutting it too close.
You might be simply rolling the dice because you have to remember expired domains do have a history.
The sad part is a lot of the tools out there will not really give you a clear picture of what the previous owners of those domains did with those names.
Do you see where I'm coming from?
You don't want to put yourself in a situation where you put in all this time, effort and energy and possibly money building up a solid brand and all of a sudden the haunted past of the domain comes back to bite you.
Talk about wasting your time.
So do yourself a favor and do some serious research.
I'm not saying that you should cut off this possibility completely.
What I'm saying is that you should have a healthy dose of skepticism and curiosity.
Otherwise, you might be simply digging yourself into a hole.