One of my solar watches was about $200, and it was a bundle with a bracelet. The other was around $800. It has a lot of other dials on it and extra features. It's not a diving watch, but it's pretty damn close in its construction.
Any light source works to charge them. I just set mine by the glass door in the kitchen because all year round, sunlight pours in through it. I left it there for a few days, and voila. It was charged.