Deciding what to collect needs time; in the early 2007 when I started collecting Macross and Gundam, I was picking up whatever I like as far as its design impresses me...
Then range of anime series I collect started to grow exponentially and at some point I was trying to pick up a figure from every series I have watched...
This habit, of course, was not sustainable
However I'm really glad that I have Yamato's AV-98 and Bandai's Swordfish even Idon't have any other figures from these series...
Now I'm limiting myself to specific franchises (Unicorn Gundam, L-Gaim, Tekkaman Blade).
In terms of Macross, I started with "One of each kind" and evolved to "Get one of every release as fas as price is not enormously inflated"