For the true LBA sufferer, the "precious" is always the NEXT lens they will acquire.
People always ask about some magic number, but LBA isn't about how many lenses you have, it's about how addicted you are to buying new glass, and how much it impacts your life. You can be a collector without being an addict, just as you can collect wine without being an alcoholic (and you can enjoy the same lens again and again!). Heck, you can only own a couple lenses at a time, but if you're constantly looking for something "better" to replace them, you still have LBA.
That being said, as one of the forum's leading collectors of Samyang wide primes, I owe it to everyone to get the 12mm fisheye, even though I have the 8mm, don't shoot FF, and resent the $50-100 extra the K-mount version costs. Besides, I've found that my 8mm and 10-17mm fisheyes are just a little too slow for some subjects, and my old Sigma/Spiratone 12mm fisheye, while fun, is crap at f/8 and even then can only be used outdoors on a sunny day...
And the new Sammy 20mm/1.8 is interesting, too...