Good opportunity if proper preparation is ensured.
Pros: work through summer, play through the rest of the year. and if you like the work it's basically year-round fun.
Cons: it's all on you. not necessarily a con if you can handle that.
Be sure to get all the training you can, and be prepared for on-call day-work, lots of travel, and potential danger. They aren't going to ensure this for you. A capable salesman/technician can earn a good living with this business assuming they're prepared.