Hi Mandy i am from Tipton so not far from you, try Bilston towards the bottom of the town for a little supermarket called Nisa (they do every type of Indian spice),plus dont forget to use the market stall at the top of West Bromwich town (the owner is always sitting on his chair at the front of the stall) for ALL of your ingredients for your curries, coriander,garlic,ginger,chillies and also sells the string bags of onions very reasonable prices as well.
Anything else you want help with please feel free to ask.