I would suggest looking instead of for cheap (where you will get spray spray spray), I would look for someone who knows about Integrated Pest Management (IPM) which uses least toxic alternatives, unless pesticides really are the way to go.
You should ask yourself what type of pests you have, and whether it is worth risking poison (insecticides are often cholinesterase inhibitors which inhibit human's neurons too) to you, your family, your pets. If you go cheap, you risk having someone who doesn't know what they are doing, spraying more pesticide for more effect (it doesn't work that way).
Anywho, I guess my point is...you get what you pay for. You pay more for knowledge, and that oftentimes is someone who will use IPM, least toxic measures, and therefore less spray. I put a site in the sources that gives you a lot of non-toxic & effective ideas to control the pest of your choice!