Question about buying and selling domains

If a keyword on google traffic estimator shows 4,400 local and 8100 global searches but the domain using the exact keyword has never been used is the domain worth buying with intention to sell?

I really don't think I want to get into flipping domains, but came across this when researching a domain for a product review micro niche site im working on and was just curious if this is a potential business model (searching for domains with keywords in them that have significant searches).

Thanks in advance for your help.

Depends , you can find domains with exact matches everywhere. Better to hold as a portfolio booster or develop later.

Would you recommend parking the domain with something similar to sedo's domain parking service in the mean time while I am developing the site or just leave it unindexed/developed?

Now lets say you can get a hold of a domain with exact keyword that has 2.2 million searches and 200,000 local what is the best way to figure out the worth of these domains?

Domains are valued for being premium ones most of the times. You can see various auctions at SEDO to check what value other domains are getting and what are relevant keywords and search stats.