Doorknock but if no one home leaf a leaflet.
If they say I got 1 already but give me your price I will immediately say Why if you have one ........... if they say you may be cheaper then just refuse and say stick with your guy .......... if they say he is a rip off merchant skips windows, argues with the missus, does a poor job, broke my sky dish, sits on my garden furniture to have lunch, charges me £130 to get my gutters cleaned but didnt acyually do the job, spits / wees on my garden, then yep will give em a price.