I assume Teslabot won't be available until its ROI has been proven in Gigafactories. Factory jobs can be simple yet still useful. For example, a bot could follow a person and carry parts, take notes while the person inspects a line, or even hold a flashlight. The bot could grab a lunch or a coffee, and double as a guard at night. You could ask a bot to go grab something while still working on a task. Unlike people who do best with a single job, bots can switch tasks constantly and make great work assistants.
The tasks may seem frivolous, but I can easily see saving 30 minutes a shift. At 3 shifts a day, and 365 days a year @$30 / hour, that would save $16k annually. Selling bots for $30k should be an easy, and for a lot more if they can perform even 25% of a FT person's tasks.