I'm New At This And Recently Inherited Some First Day Covers

And it isn't addressed! The 2011 catalog value for the FDC of the Postal Service Emblem issue was $1.00 and an estimated 16,300,000 were produced. There is a note indicating that first day cancels from over 16,000 cities are known and that some are rare; unfortunately, it doesn't tell you which are the rare ones.

I'm assuming that if they are addressed,even if it's a rare first day cover, the value goes down. I'm I right?

It depends on a number of factors, including when the cover was produced (see the catalog extract in my earlier post).

I think that odd don't you? If that be the case, (having no address) then it would be a rather bland and unbalanced looking cover wouldn't it? I like to see peoples handwriting and a nicely filled out cover with or without cachet. I have to wonder why people would prefer the unaddressed covers anyway?

As previously mentioned value will usually depend on a number of factors and in the case of no address I look for unaddressed covers if the cancel itself, even on first day covers, is of significant interest. Sometimes the handwriting makes it more difficult to see the entire cancel. No address can make it easier to distinguish among cancel varieties.

these sell for 10 to 12 dollars each at my stamp club auctions

Here's a website that attempts to identify all of the various postmarks known for the USPS Emblem issue of 1971:

http://www.remcatalog.com/Default.aspx

Although I don't know that I necessarily agree with the methodology of how they attached the stated values to these covers, it does at least give collectors a general idea of the common versus scarcer known postmarks. The Willows, CA postmark is said to be REM #051862 and is valued at $6.