I did not realize they were hardy to zone 5. I am in zone 7 and protected mine under a porch til this year.
In my area a 5ft one is about $90. But I ordered mine over the internet. To my dismay they are no longer seller on the internet. It seems I paid about $35 for a 2ft one. I order 3 different sizes. Small, Medium and large. The smaller one died down but it has some new babies. It takes years and years to get a truck.

Here is a link that might be useful: Blue Yucca-Probally a 4inch pot or a quart.