In Virginia for items purchased on the internet over $100, sales tax must be paid. Is that amount of $100 per item or total?

I purchased 5 items from Amazon for which no sales tax was charged.  The items ranged from $10.93 to $57.99 per item.  All together they total $161.38.  My question is: Is the $100 limit per item or for the total?  I live in Virginia.