most likely, I would pass. How long has the domain been registered? Just because it is set to expire means very little, if the domain has been registered long enough, then there is a good chance that it will be renewed again, and just because it expires does not mean you will be able to get it as the domain will go through x amount of time before it is released to the public, then there is a very slim chance that you will get it then because domain companies grab domains very quickly then put them up for sale at crazy prices.
I only go with dot.com domains, and if I cant do that, then I keep looking until something fits, and the only time I buy secondary domains like dot.net, dot.info. dot.org is if they are avail that matches dot.com as they are far less popular then dot.com. You can always think about which girl you like best, you want girl #1 however, she is not available, so you go with girl #2, which means you just end up settling on something less than perfect. I would rather go with something that I want, or not get it at all, as I do not like to settle, and develop something on 2nd, 3rd, or 4th best.