Markets in London

[lindenharp]

I need to know which of the London street markets has a reputation for cheap, tacky goods.  The context is Nine being snarky about a suitable place for Rose to buy a gift for her mother.  Or a chain store would do if it's sufficiently low quality.  They won't actually be going there -- it's just going to be mentioned in the dialogue.

Thanks!

ETA:  Thank you to everyone who responded.  It looks as though I'll be going with Poundland or Poundstretcher.  Those will translate very well for American readers who are used to dollar stores.