You're way, way off in your numbers.
Average property price in
West Ham is £375k. Yes,
not £2mn like Mayfair, but also not £70-150k.
In fact if you search for properties in
West Ham under £200k, you see only 3 properties, one is a shared ownership, another is a lifetime lease for 60+ people, and the third is a minimum price for an auction. The first two are 1-bed flats, as well.
For a 2-bed flat in West Ham you're looking at the £275-350k range. If you want a nicer one, it's closer to £400k.
I'm guessing you haven't been living in London for a good while if you seriously thought a 2-bed flat in West Ham is £70k