$21 is for the whole fixture. Ballast and bulb. They can be ran inline with each other up to 10 fixtures on one power cord. Will provide reports further down the line. No more tons of wires to run into a power strip. They also make chillers and other lights. The orbit light is a current usa light. The prime chillers are current usa items. Here's the link to there website
Current USA
And As far as the actinics, they are a crisper blue, brings out more color than the VHOs I have.