If you’re interested in keeping a rat as a pet, you shouldn’t be concerned that the expense could be an obstacle.
Rats are very inexpensive to keep as pets, as their food is really the only thing that you may have to spend money on for them.
But rats are true omnivores, and can eat just about any type of organic material, making it quite easy to feed them.
Rats prefer the same type of food that people do, so if you are concerned about keeping costs down, you can feed your pet rat leftover food scraps from your own table.
The only other type of expense that you may face with a pet rat is the occasional trip to the veterinarian, which should not be very often.