This exact arm costs about $140 new. Most street light arms run in the $125-$400 range (the $400 ones being big truss arms). There's a huge markup on this stuff for reasons I don't know. Same with traffic signal equipment; that stuff is outrageously priced (and red-yellow-green signal head goes for over $400 new!) though I get the traffic signal equipment being pricey because it's "safety" equipment.