Wow as mentioned the sky has fallen. Have you tried talking to the WV DMV. They may not issue temp tags but then again they may. I took a quick look and in one place it says they dont but on another page at the http://transportation.wv.gov/dmv/vrs/Pages/default.aspx it clearly mentions temp tags.
On another note and I have not used one in many years but I have gotten "in transit" tags before. IIRC the last one cost me $5 and was good for 5 days or something like that a quick google came up with this for WV
https://apps.wv.gov/DMV/TripPermit/Individual/Default.aspx?ReturnUrl=%2fDMV%2fTripPermit%2fIndividual%2f might be worth asking about it at the local dmv
I personally would have no problem driving the vehicle home with the out of state plate or no plate as long as I had title, proof of insurance and bill of sale with me. While it could possibly end up with a ticket/s you would have to be a real tool leo to issue a citation if you had all the ownership proof and heading home but if they did no big deal they would be doing their job, they are usually no points. Impounding the vehicle seems quite outlandish and I do not see it listed as a potential consequence in the previous listing of consequences provided by a previous poster as does jail time for misdemeanor traffic offenses. However if you were to get cited in each state you would probably be better off paying the double tax. Perhaps you can mitigate it a bit by having the seller meet you at the Georgia Florida border if you do not use his plates.