If you're a small business with many employees it makes sense to setup your own internal computer network.  However, setting up and running the network requires purchasing the equipment and hiring skilled network managers. 
 
Having your own network manager comes at a high cost.  Experienced IT people with this kind of skills don't come cheap.
 
You can't avoid purchasing networking equipment but you can avoid hiring network managers by outsourcing this function.
 
The downside to outsourcing the network manager task is that you have to trust an outside entity with access to your data.  To over come this fear you have to do your due diligence and check on the company's background and review complaints agasint the company.  You can also take full control over any sensitive data and keep the consultant from accessing it.
 
The up-side to hiring an outside network administrator far outweight the downside.  Cost is one factor.  It is cost less.  You don't have to pay the salary and benefits.  The consultant will ensure that someone is available to respond to your request for service whenever you need it. 
 
Click here to take advantage of resources for outsourcing network setup and management.
 
Use this IT Consultant Checklist.