This was the last pot on the shelf and had no tag...anyone know what variety it is?

Some Agapanthus are short.
Other Agapanthus are really tall.

According to Wiki there are 7 sp.
But there are also numerous named cultivars.
Quote wiki..."World Checklist of Selected Plant Families recognises seven species:"

Hard to even begin to take id any further.

There are enough similar-looking Agapanthus cultivars that I doubt you will be able to be certain of an ID, unfortunately.

too many varieties and possible variances within those varieties.

Blue Yonder, Margaret, Galaxy Blue, & Blue Yonder are just a few that are a little more stripey..
Ask the nursery manager if they can tell you what was ordered..