One thing i would advise is keep the old dpf. If m.o.t's change you could be looking at the car failing without the dpf being on & aiding emission results.
You can always clean the old one & re fit if things change & I'm 99% sure if you cleaned the old one it will give you another 50k miles.
I was thinking of putting mine on ebay but I will just hang on to it as I don't think mine is anywhere near blocked. Would have been just my luck to flog it then find out the rules have changed & I have to buy a new one..........
£600 fitted with a tune & dpf software removal is a good price. (having taken mine off with the help of my mate who is a mechanic & has his own workshop) I paid £350 for the pipe so that would only leave £250 for labour & remap.