Since I am Indian, I frequently shop at the South-Asian grocery stores. Nowadays a lot of supermarkets have started selling Indian frozen entrees (eg, Whole Foods, Trader Joe’s or even the local supermarket sells Amy’s frozen Indian meals) but the most authentic and reasonably prices frozen entrees are at most South-Asian grocery stores. These stores have a wide variety of frozen flat breads (Naan, Tandoori-roti, Paranthas etc…) that are quite reasonably priced.
The best deals South-Asian stores are on all kinds of spices. You can get prepared spice mixtures for various South Asian dishes (I use Shaan spice-blends for most non-vegetarian dishes and can almost not do without them!) and also individual spices in small packets. For instance, commonly used spices such as cloves, black-pepper, cardamoms (green and black), cinnamon, coriander, cumin, nutmeg, mace, turmeric, mustard seeds and even saffron are available at all South Asian stores. They also carry spices that most non-south-Asians are not familiar with; such as Asafetida, Fenugreek seeds, Fenugreek leaves, Kalonji (onion seeds). There also sell specialized dairy products and sauces that most non-South-Asians are familiar with (from eating at restaurants but don’t know where to buy them), such as: paneer, ghee, sweet tamarind sauce or green Coriander sauce.
If you are a tea-addict then do visit the Indian stores in your area – they carry a wide variety of loose leaf teas and also tea bags, which are lot cheaper than specialty tea stores such as Teavana and Teaism. I highly recommend the Lipton Green Label Darjeeling Tea – it is a good quality black tea which I am completely addicted to. Also good quality Basmati rice and whole wheat flour are a steal at Indian stores.