Can you use a blender to make wheatgrass juice?!

Nope, you'd only have slightly bruised grass when you're done. You could try running it for an hour to see what that would do, but if you can't wait that long then you're probably out of luck. Not sure if soaking in warm water would help soften the grass, but you could experiment. The only blenders that might do the trick are the high powered, and highly expensive brands like VitaMix or Champion. They are great for everything (especially hummus) and I'd definitely recommend them, but they'll set you back about $500.

Some juicers are specific to wheat grass, so those for me were too impractical. But if you are primarily interested in wheat grass juicing you could check them out. I did get one called a Tribest Z-Star, which is manually operated and can be used for many kinds of juice. It is reasonably priced.

But as I said before, if you're not in the market then you're probably out of luck. Believe it or not, you could chew on the grass and try to extract the juice that way. Oddly enough, that's about the same thing you're doing by using a wheat grass juicer, just takes a lot longer.

http://www.zstarjuicer.com/index.asp

A wheatgrass juicer is different from a regular juicer.
You can try using the blender by adding water to the grass, blending, then straining the shredded grass through a sieve and drinking the wheatgrass juice/water. Obviously, it won't be as potent as if it were juiced..
I would check out Target and other stores...I got my regular juicer for $40...it's doesn't juice wheatgrass, but you can get most of the same nutrients from juicing other veggies and greens.

No, a juicer takes away fibers from the plant which turns it to juice, it collects the "pulp" on a vent like slide on the back, I've seen. You could try it, I'm sure, but it surely wouldn't come out too well.