You might have had a little better response if you posed your question a little bit better. I am not trying to chide you here, its just that I think I know what you are asking, but the way you worded your post, I am guessing at best. I understand with the internet these days, you want to be brief and I understand that, but in reading, and rereading your post, a few more specifics might have helped.
Now to answer what I think you are referring to, I think for making signs you will want to get a plunge router. Now I do not make signs myself, but my father did and he did get by with a standard router. Still he could have done better signs and done them faster if he had a plunge router. It is definately worth the money.
Just as in life, the more money you pay for a tool, the better off you are. The problem with the cheap routers are the 'sleeve bearings" that come with them. They are mearly chunks of machined bronze for bearings and don't last very good. Ball bearings are expensive, but when a tool is turning 7,000-28,000 RPMs, sleave bearings are going to wear out in short order. The problem with that is, when you are making signs, you are using one tool for along period of time. That is punishing for a router.
The bigger, more expensive router you get, the better it will last. My father had a cheap Craftsman that lasted for years surprisingly enough, but he only made a few signs a year. For someone making a decent living, or a decent supplimental retirement income with sign making, I think they would be better off getting one that is a plunge router, of at least 1 1/2 HP, and takes a 1/4 or 1/2 inch bit. But of course, this is just my honest, but humble opinion.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"