Glens Army Navy has Federal XM193 5.56 x 45mm 55 Grain FMJ BT for $129.95
per 500 plus Shipping. For two cases, 1000 rounds shipped to Oregon was $277
.79. Just under $.28 per round is about the best deal going right now.
Link: https://www.glensoutdoors.com/ProductDetails.asp?ProductCode=XM193F&CartID=1