I don't know Philadelphia but here are some general tips to reduce food/home products prices -
There is probably a Community Supported Agriculture (CSA) group in your area. You pay money in the spring so local gardeners have funds for seeds, etc. The money is a "subscription." When crops are ripe, you come pick up your share. In our area it's $225 for 1-2 people for a year. Families are about double. We pick up the produce on Fridays or Saturdays during set times. We get produce May through September. You don't pay more. If you work in the gardens, you usually get a discount. Produce is often organic.
Another group are food buying groups which get produce from local farmers. These are less popular but you might find one.
Farmer's Markets in the summer can be great sources for local produce and cheese. They are usually held on Saturdays. They can be fun places to go on a Saturday.
At the supermarket, shop along the walls. That's where the produce, dairy, and meat are located. Expensive, low nutrition cereal, jams, etc, are in the aisles.
Dollar stores are great for paper things like toilet paper, kleenex, etc. I would never buy canned or bottled food there. Too much comes from China and contains low quality contents.
Costco is a terrific place to buy food and household items. You pay a membership once a year and get a card. Usually items are offered in "bulk" - meaning you buy toilet paper that has 8 packages of 6 rolls per package. You might ask friends to come with you when you shop so you can buy one container of toilet paper and split the cost and goods after you shop.
Pick up a breadmaker at the thrift store and make your own bread. You can save hundreds a year if you love bread.
Buy a Slow Cooker (aka Crock Pot) and cook all kinds of inexpensive poultry and meat in it. I like to buy boneless, skinless chicken breasts for cooking in my slow cookers. Then I put meat in baggies then freeze. Use in all kinds of soups, casseroles, salads, etc. Borrow slow cooker cookbooks from the library.
In the grocery store, look for generic brands. I love A-1 Steak Sauce. My local store has a copy-cat version just as tasty for much less.
Hope this helps!