If you are looking for the best entry level pro scooter, my recommendation is the Flow X by Madd Gear Pro (also known as MGP).
Several reasons why I recommend this.
First, MGP makes a great line of pro scooters, starting with this Flow. They are all well constructed and built to last.
Second, the design of the Flow is similar to that of larger pro scooters that the intermediate and pro riders like. The T bars (in the shape of the letter 'T') are common in higher end scooters.
Another reason is the design of the neck (the part of the scooter between the headtube where the bars fit in and the deck where riders stand). Notice that unlike other entry level scooters, MGP put some thought into the design; see the comparison in the picture below:
Speaking of design, the Flow has a little edge to it. Note the skull emblem on the headtube (see picture above) and on the wheels. Kids like skulls for some reason. Even the grip tape (where the riders stand) has sharp, contrasting blue designs.
Two additional key points; weight and price.
The Flow weights right around 7lbs, which is a great weight even for younger riders. This is slightly heavier than the old fold up Razors, but the added weight is a good thing. Young riders, and even older ones, like to have a little more substance to their scooters.
$119.99 is a great price for a well-built entry level pro scooter. Sure, you can spend more, but I wouldn't recommend it until you know for sure your young shredder is going to continue in the sport.
To recap, designed and built by well known company, has the look of older pro scooters but with an edge (but not too edgy), right weight and great price. Best bang for your scooter buck...MGP Flow pro scooter!