Cheap fix/Labor of love: I had the same problem up until friday, I went to shuck's (now Oreilly's) and got a new EGR valve gasket for 2 bucks. Then went home and took my EGR valve out with a size 12 socket and first cleaned it thoroughly with throttle body cleaner and used an old tooth brush to clean the insides from gunk and carb build up and rinsed it some more with tbc. After doing that, on the egr valve itself, I repeatedly moved the plunger part that goes up and down to make sure that I rinsed and cleaned it well. Then I got a bowl and spray-filled the bowl with tbc and dropped my EGR in it and let it sit for a good hour or 2. Grabbed the EGR, moved the plunger part up and down again to let all the tbc liquid out of it, dried it with a shop towel and installed it back. Make sure you get a new gasket however, as you wont be able to use the one you take out.
O'reilly's: ...has it for $170. Honda has it for $300... It's a crying shame but you pay for what you get - an OEM part will typically last you a lot longer.
Hope this helps and good luck!