Also, keep in mind the LFS is meant to be a temporary home. I have picked up some not so happy corals and anemones from my LFS and once they are in a my tank and in a more stable system they "perk up" and look much happier and healthy. I'm not an expert on anemones but this one looks healthy but just not happy as those above have said. Just wanted to make that distinction, because if you have a good setup and have experience then it looks like an acceptable specimen. Unhappy anemone is easier to fix than a sick anemone.
They can be mixed with some caution, but I'd pass on that specimen. For LTAs, it's best to find one that's well attached and has some good dark color. LTAs are somewhat hardy (at least when compared to some other nems, looking at you carpets and magnificas) but they still take a while to get back into good shape, and recovery isn't certain.