I'm looking for a flash under $50 for both off and on-camera use. Currently, the pop-out flash works very well for indoor/night photography. I would just like a little something to play around with (since I've never had a flash before); something to use with my homemade flash diffusers or as a bounce.

The reason I came here for help is because I'm having trouble finding a flash with both optical slave and variable power for under $50. As an alternative to optical slave, how much do the so-called "ebay triggers" normally cost?

Here is one I've stumbled upon
-Digital Concepts 418-AF Slave Flash - $30
but I can't tell if it has variable power. I'm thinking the ISO knob is only for shifting the upper grid behind the window.

here's the manual
and here's a larger picture