Is there a way....
 

to do a search where you look for flights within a certain price range. For example: any flights on NW/DL originating in DTW for less than $150.00.

I have not had any luck using the search tool and being new, I have certainly not read all of the various threads available. Thanks for any suggestions you might offer.

The best website that can do most of what you want: http://www.farecompare.com/search/flyertalk.html

What you want is the FareCompare FlyerTalk search page, sorted by total price rather than CPM.

http://www.farecompare.com/search/flyertalk.html

HEY.... isn't that what I said? :)

OK, I have been to FareCompare often. If I put in DTW I can get the "selected" flights and the CPM. Currently there are no flights listed at less than 6 cpm. OR I can sort by total price and again I get a couple of dozen selected cities. Is there any way to further filter? That is, list ALL cities at $150 or lower? Thanks

Yup...you type faster than me apparently. :p
Umm...if you are sorted by total price then you are seeing all the cities priced at whatever threshold you want. You might need to go to the second page of results, but the net effect should be the same - the fares are all there. There aren't many (only 5 that I see, three of which are to the same city) fares under $150. Under $200 open up many more options for you.

This one works for me on occasion.
I have no idea where it came from, but it can be useful.

http://indiakane.com/ff/ff.jsp