I'm new to Audi ownership but regularly cleaned out the EGR value on my mk5 888 Astra.
I'd get YouTube searching on how to change the EGR value before handing over that kinda cash! EGR exchange took 15mins to swap out on my old mk5 Astra!!!!
i soaked my EGR value, and I mean soak the EGR value on the first clean, then went to town with a pipe cleaner/toothbrush. You need to clean as much as you can..doing just on the outside surface of the EGR value will not fix the issue. You need spend about 60mins on that first clean, if youre done in 5mins, you're not Cleaned it enough...
good luck..