Source: Shutterstock IAA (NYSE:IAA) stock is climbing higher on Monday thanks to a massive acquisition deal with Ritchie Bros Auctioneers (NYSE:RBA). Ritchie Bros have agreed to acquire IAA in a deal worth $7.3 billion, which includes its assumption of $1 billion of debt. The offer includes $10 in cash and 0.5804 shares of RBA stock…