It really depends on how much and how hard he rides. The Razor Ultra Pro is actually a pretty good scooter for the money and holds up well for beginners. The downside of it is that it is hard to upgrade and is very low on the cool scale. Most scooters have threadless forks whereas the Razor is treaded. That pretty much means you need to upgrade the fork, headset bearings, compression system (clamp) and bars all at the same time. My 9 year old thrashed his Ultra Pro in about 6 months. If he rides a lot and you can swing it, go for a District complete (about $300 vs. $80). It will last longer and as he gets older he can start customizing and replacing individual broken parts. Stay away from anything in-between (shawn whites and madd gears). They are usually heavy and the components are not very good.
P.S. I usually make my kid put in about 1/3 of the cost of his scooter stuff. It helps if he has some skin in the game.