Printing can be a huge cost for a company wishing to advertise using leaflets or brochures. Not only will they have to pay for the design cost but also for the printing itself. Printing costs can vary drastically from company to company but sometimes there is a reason for this. You may find that cheaper printing companies do not offer the same quality of print that you would get elsewhere. Ideally you need to see examples of work that they have done and even have samples to take away and compare with other print companies. There are advantages to using a local company as you can always go and pick up your literature if needed to save time and delivery costs.
Make sure that the printing company has a policy in place than insures any material that is not printed correctly (and it is the fault of the printing company) will be reprinted free of charges.