There is nothing you can buy, unless you are a licensed pesticide applicator, that will control any of the sedges. All of the sedges, including Yellow Nutsedge the most common of the sedges that grow in out yards, grow most bestest in moist soils, because they are bog plants. So if you have a problem with a sedge growing in your soil look closely at that soil and figure out how to make it less nice for the sedges to grow in and then you will not need to spend your money on sprays to try to control it.

Here is a link that might be useful: About Yellow Nutsedge

Kimmsr, if you read the many posts about nutsedge in the forum, you will (maybe) come to understand that these plants are an aggressive weed in all kinds of soil conditions. To repeatedly tell people to fix their moisture problems, year in and year out, is getting a bit strange.

Alf, I'm afraid that you will have to bite the bullet when it comes to nutsedge control. Image and Sedgehammer are both pretty good about controlling both the purple and the yellow nutsedge. I honestly don't know of any 'cheap fix'.
So the cost effectiveness actually boils down to effectiveness, period. It would be a waste of your time and money to use something that might be a lot less expensive, but won't do the trick. Right?

Shop around in your area to find a good supplier of agricultural and landscape management chemicals.

Prior to my retirement I was a Grounds Maintenance Supervisor for an athletic department at a State University. We had yellow nutsedge problems in some of our fields. I found that Basagran was very effective in controlling nutsedge and also some broad leaf weeds.