The main issue with linkas is acclimation. Even if you do it right, you don't know if the distributor or retailer did. It can take them a full two weeks to start dying from bad acclimation. If you geta good one, they tend to live a long while.
If you can find some Fromia monalis stars, they acclimate very well, are very hardy, and not too expensive. But they're as hard to find as they are hardy. If you can find them, don't pass up on them. They can vary in appearance greatly, from lots of white to very little.
http://www.edge-of-reef.com/asteroidi/ASTFromiamonilisen.htm">http://www.edge-of-reef.com/asteroidi/ASTFromiamonilisen.htm</a>
The Fromia milleporella is a good substitute for that one, also.