Shopping as a business is an ok business for certain people. If you like to meet and talk to people and get out and about this can be a good business for you. It probably won't pay well unless you have wealthy customers that are willing to pay you well. It would be difficult to price your service. There would be a wide ability by customers to pay. Some will need help getting groceries and other necessities like medication and other important products but some potential customers will be living on social security and can't afford much. You will not want to turn your service into a charity but you will likely have a few charity cases. Some will help you get more customers so any customer can be good to start out. By making it known to people you know in your town you should be able to get some customers. Let people know you are in the business.
Of course you will need a car and a cell phone but that's about all you need for this business. The most difficult parts is getting customers that will pay well. As time goes on you should be able to get a better clientele, with some paying you more than what you ask for. Because it will be difficult to price your services it may be best to price by your customers ability to pay but that is a tricky way to do business. Working on tips may be a good way to go. Some people will like you and pay you well. With businesses like this were you deal with people so closely it's important people like you and is a major factor in how well you will do.
With the price of gas being high, it will run you some money buying gas so it's good if you have a fuel efficient car. High gas price will also be an advantage because people may be interested in others driving than using their own gas guzzling car. A hatch back, station wagon or mini van will be better to use so you can carry groceries or other things people want you to buy for them. Although groceries may be something that most people will want you to buy there are many idem's that people would like someone else to shop and buy for them. You should tell people what you will shop for. Some things you may not want to carry, like large and heavy products like lawn care products.
If you like shopping it will be an advantage because you will know where to get good deals and the use of coupons or looking for sales in newspapers can make you popular with customers and can help you make more money. If you can save people money they will appreciate it and reward you. At times of the year like Christmas you will likely get larger tips and gifts. Some will offer you things they do not want. Many have all kinds of things around the house and may be happy to give to you. You can make some extra money on the things people give to you by selling them on ebay.
Overall a shopping service business is for certain people. It won't pay well but if you like shopping, seeing and talking to people you may enjoy this business.