Why does it need a new one, can you not just take it off and clean it with carb cleaner which will cost no more than £10 and take about an hour. Its an easy job for any one to do. Alternatively look at dark side development for the egr delete kit, think it costs about £90 but will bring a light on the dash. You need to remap to get rid of this so I guess you will have the extra cost for that also and to ensure you keep it running like you have it now. I would explore the first option if I were you