There are certainly benefits to having a local mohel. But there may be cons to having a local mohel too (See here, and here, and here, and here.)
Think of it this way - many people who require a delicate surgery will travel across the country, or even across the globe, to go the "best" specialist in the world.
For your son's bris, the specialist will come to you! (I do not claim to be "the best," which would be presumptuous, but there are things I offer that you won't find elsewhere -- see the end of this posting and here.)
Let's talk about whether it is indeed cheaper to use a local mohel.
If your local mohel does not take a fee or takes whatever you'll give him, then yes, your costs with the local mohel will be lower.
But if your mohel has a flat rate of $500 or more, then you can begin to weigh options.
Here is what I ask for you to cover/arrange.
HERE IS THE BOTTOM LINE:
If you are strictly looking at things in terms of dollars and cents, weigh the options and decide which will cost less. Call me - let's see if we can work it out.
If you are weighing other components in your decision, I can help you explore those ideas, to help you discover the best option for you. (go to my other blog, and search "important questions"