The following sterling silver ball earrings are priced per pair and come with backs.  
You can mix sizes for the ball stud earrings for quantity price breaks.

2mm Silver Ball Stud Earrings These earrings have a 2mm bead on the top and are very tiny. 1 for $1.00 each 6 for $0.75 each 12 for $0.50 each Quantity:	3mm Silver Ball Stud Earrings These silver earrings have a 3mm bead on the top and come in a pair with backs. 1 for $1.20 each 6 for $0.85 each 12 for $0.60 each Quantity:	4mm Silver Ball Stud Earrings Silver ball earrings with a 4mm bead on top 1 for $1.50 each 6 for $1.00 each 12 for $0.75 each Quantity:	5mm Silver Ball Stud Earrings Sterling ball earrings with a 5mm bead on top 1 for $1.80 each 6 for $1.25 each 12 for $0.90 each Quantity:
6mm Silver Ball Stud Earrings These SS ball earrings have 6mm beads on the end. 1 for $3.00 each 6 for $2.25 each 12 for $1.50 each Quantity:	7mm Silver Ball Stud Earrings These SS ball earrings have 7mm beads on the end. 1 for $4.50 each 6 for $2.75 each 12 for $2.25 each Quantity:	8mm Silver Ball  Stud Earring A very popular silver bead earring, these have 8mm balls on the end. 1 for $5.40 each 6 for $3.50 each 12 for $2.70 each Quantity:	10mm Silver Ball Stud Earrings Sterling ball earrings with a 10mm bead on the top. 1 for $7.50 each 6 for $5.00 each 12 for $3.75 each Quantity:
Sterling Silver 12mm Ball Leverback Earrings These eye catching large drop earrings are perfect for any occasion 1 for $11.95 each 3 to 6 - $8.25 each 7+ - $6.50 each Quantity:

Please note throughout the site that gram weights and measurements are approximate. 
If you need to know in inches the size of a piece of jewelry, click here - Millimeters to Inches