I spoke to a past stage tech PI who told me that it's $8.92/hr for them, and around $11/hr for entertainment production assistants. Though she did say that what you make as an intern might be higher than the base pay for the position you're applying for.
She said that the base pay for FT stage techs was $12.50/hr & for Entertainment Production Assistants that it was lower than $11/hr. I'm actually hopeful that it varies person to person because I have extensive experience doing Stage Tech for various companies in the area, and my base pay for them is more like like the FT base pay, than that of the internship pay.
Though I'm more worried about trying to live on $9/hr
Oh, and if a position is missing from your workbench, I'd say it's been filled as the Costume Design Position is still listed in mine, and I know I got "bumped" from it.