Where are you guys finding OEM RBs for around $500??? The X5 Accessory book I have (which is old my dealer told me when I went in there to get some stuff) shows the RBs are nearly $800

My girlfriend is 5'0" and was already looking to use the stock bits as a step, which I don't think it was really intended to be so I'm thinking this might be a required mod for me.

Also, where would be a good place to get the rivet gun mentioned as being needed for the install? Any advice on brand/model to get?