I do not put a lot of stock in buying LR
from the LFS
because who really knows where it came from. More than likely it was base rock that they seeded there at the store. I would go with what looks best to you (visible life and coraline growth) for the money.
Unless you are setting up a reef right away or planning on the rock to be your primary filtration I would save my $ and buy mostly base rock and seed it with a small amount of LR
and put the $ into better lighting to promote coraline growth or other equipment.
Basically all rock is LR
in a few months it just may not have as much visible growth and hitchikers that may come on LR
from an LFS
or purchased on line. This is the route I went. I have only ever bought about 10-15# of actual LR
If you are set on buying a large amount of LR
up front I would check online. I have read many posts on some of the quality stuff out there that I am sure others can comment on from first hand experience.