When looking for an affordable graphic design company, look for one that is big enough to cover your needs, but not so big that you’re paying for layers of unnecessary overhead. A well-run design company with a team of up to twelve people or so is probably that sweet spot between depth of skills and cost-efficiency for most small businesses.
Keep in mind that the cheapest option is not always the most cost-effective option in the long run. So many clients come to us on the heels of a failed project with the cheapest graphic designer they could find. It is always more expensive to do a project twice than to do it right the first time.