Cheapest place to buy birkenstock madrid in narrow?

[Yorkshirebornandbred]

I've looked everywhere but can't find them for less than £50. My old ones are falling apart .. I wear them everyday all day, they're the only thing that help with the pain of plantar fasciitis for me.

TIA

Depending on size, try Surfdom, Spartoo or Amazon all have Madrids £30-£40

Thanks. Everywhere I look the slim fit ones in my size are over £50.