My husband and I just returned from London where we viewed properties in the Harrow area (Pinner, Harrow, Stanmore, etc.).
Surprisingly, the estate agent we worked with from Foxtons Pinner (of all places!) was really great. His name is Sean Packer. He showed us 4 properties in the general area. We saw a newly-built 3 bedroom semi, 2 renovated Victorian terraced houses (a 3 bedroom and a 4 bedroom), and a 2 bedroom modern flat. All of the properties were under GBP2K a month. You'll definitely get more for your money in that area rather than in areas closer to Central London.
Pinner tube station is on the Metropolitan line. Rayners Lane station on the Piccadilly and Metropolitan Lines is also in Pinner, about 1.4 miles from Pinner high street and the Metropolitan Line station. It takes about 35 minutes to get to Central London on the Metropolitan Line (not sure about Piccadilly since it comes in via Acton Town) .
There's a big Sainsbury's right in Pinner next to the Metropolitan line station. The high street(s) are your usual small suburb, with banks, charity shops, takeaways, etc. The old high street in Pinner has a lot of charm. My husband and I really liked the area.
Hope this helps!
Di