Steam Controller, Valve’s next-gen gamepad, is slated to launch on May 4th for $100, although you shouldn’t expect to see a big ‘buy’ button next to Steam Frame or Steam Machine. Speaking to Polygon , Valve revealed that it’s only releasing Steam Controller next month for a pretty important (and slightly obvious) reason: Steam Controller “doesn’t have RAM in it,” Valve hardware engineer Steve Cardinali told Polygon . “We wanted to build up quantity so that we could try to address everybody who wants one at launch,” Cardinali maintains. Image courtesy Valve Notably, Steam Machine is set to include at least two bundling options: one with a Steam Controller and one without, which could put a kink in Valve’s supply efforts to produce enough Steam Controllers, as Machine specifically features built-in support for the gamepad in an effort to make it more of a living room console.…