@awfulart3
First, Thank you for your service.
Second, I would suggest that, if you target "inexpensive," you could be sacrificing quality or condition. If your camera does not capture video that meets industry standards or if it fails to work properly, you will be wasting both time and money. Be prepared to spend $350, give or take.
That said, your message suggests that you are not ready to lay out large amounts of money and that you are new to shopping, in general. Moreover, you may have some limitations in how much and what type of shopping you are able to do. My suggestions below are based on those presumptions.
Don't start with video shopping. This requires an immediate expenditure of a fair chunk of cash and if you find that this is not for you, you will be out the cash as well as a fair amount of time. Start with regular mystery shops that require no special equipment. You can start with grocery stores, gas stations and other types of business you frequent and where you are already spending money so that you are working in familiar settings and are not spending money that you would not otherwise spend. Open a bank account (through a mystery shop so you get paid to do it, of course!). Have all your mystery shopping money go into that new account and maintain the balance you need to support shopping habits. The rest can be transferred to your current bank. Other shops that you can often start to do as a beginning shopper that don't require any cash up front: apartments, car sales, bank inquiries, various phone shops, and more. You can also find shops that will cover expenses that you would have in day-to-day life, such as oil changes for your car.
Keep in mind, however, that pay is not instantaneous. Every company has different policies. For the most part, you can expect to be paid (and reimbursed!) 45-60 days after your shop. Some companies will have you paid within two weeks. Others might take four months. So, make sure you know when each job will pay/reimburse you and don't spend anything that you need right away.
While you are exploring shopping possibilities for yourself, make a note of any video shopping opportunities in your area. Then, do similar shops without video, just to see if you are going to be comfortable with that type of shop, in general. If you find that type of shop to appeal to you, start doing a lot of them. You want the shop to be second nature before you try to do it with video. For your first video shop, you will not want to have to worry about anything other than whether or not you are doing the video correctly.
Once you have accumulated enough cash in your shopping account, buy new equipment from a vendor that will stand by the product. I believe that most shoppers have had good experiences with Greyhawk.
You are right: As you get going, video shops will pay better than most other shops and you can earn enough money to modestly support yourself, if you do not have too many physical restrictions.
Hard work builds character and homework is good for your soul.