ebay has a few, e.g.:
http://cgi.ebay.com/ebaymotors/Weian...=p4506.c0.m245

Weiand Action+Plus intake manifolds are designed for use as stock replacements, with improved power and torque characteristics. They're 180 degree, dual plane types, with a carburetor flange that'll accept either stock or aftermarket performance carburetors. Their effective rpm range runs from idle to 6,000 rpm. With their high-flow runner design, and ability to produce increased power with little modification, it's no wonder these manifolds are so popular.

Located in Washington State - shipping would be reasonable.

Current bid is $75

Summit has new manifolds from $139 plus their infamous "handling" fee.

Craigslist in Anchorage has the following:
This combo came off of a 66 Mustang coupe that I had years ago. I am not sure how old they are..... The manifold is an Edelbrock Streetmaster and the Holley carb looks like a 4150 or 4160 series....Ck out the pics and give me a call @ 745-1867. I am asking 150.00 for the combo....thanks for looking.

http://anchorage.craigslist.org/pts/1364917641.html

Check em out - there's bound to be something in your budget.