In reply to IvanD:
Not quite as cheap, but the pizza van that appears on the campsite does a very passable pizza (though they often seem to struggle to understand 'sans olive s'il vous plait'), the pizza place at the Grand Roc on the walk in to Argentiere is also good, and the Cafe La Yaute next to the campsite do great food and beer but are quite expensive.
And most importantly, both the bakery near the garage and the bakery above the Super U in Argentiere are fantastic.
But none beat Poco Loco...