I guess there are three types of LBA:
The first grade of LBA where there is a hole in your lens line-up and you "need" to fill it up (even though you may survive with other lenses with just using them differently). This is based on real need. The least severe grade.
The second grade of LBA where you already "have everything you need" but just want to try other lenses just to know how they behave. Or to fill the tiniest holes in your lens lineup. Not really based on need but for feeling. The medium severe grade.
The third grade of LBA where you want to own the lens just for owning it. Not because you need it or use it, just because you want to own it. This is based on obsession. The most severe grade (which will bankrupt you eventually).
I guess I'm at second grade at the moment. This can also be combined to CBA (camera buying addiction), CBBA (camera bag byuing addiction) or just ABA (accessory buying addiction). Or FLA (forum lurking addiction). These all combined can take all your time and money without you taking any pictures at all. That's ultimately the worst case. I have thought many times going back to first grade but I just can't
And I hope I never end up to third grade. That I cannot afford. But when I look at it, last year I got
K-5
DA* 16-50/2.8
Sigma 50-150/2.8
Sigma 10mm/2.8 fisheye
Sigma 28/1.8
DA 35/2.4
Samsung NX10+20mm+30mm
Manfrotto tripod with ball head and panorama head
If I remember correctly, I wrote about year ago in some thread that I will be buying fast sport zoom and long tele and nothing else. Maybe K-5. That really didn't work out. So I'm not promising anything anymore