Roughly 3 million apiece for a Stryker. Or for serious convoy escort, use a lowboy flatbed trailer instead, and carry an old *obsolete* M48A5 or M60A1 tank on it, cost roughly a quarter million apiece.
Is a Stryker with a .50 mount that doesn't work and a 40mm Mk 19 that's an outright danger to its own crew [live firing suspended at Ft Lewis; and at least two US casualties incurred when a crew in Iraq had a weapon discharge during an attempt to clear a feed jam- not to mention what happens if a ammo box full of HEDP rounds takes an RPG hit] more effective than a five or six-tank convoy support platoon for the same cost?
Field expedient fighting vehicles like the Alabama Slammer don't make anybody any money and provide no lucrative career opportunities for retired generals.