my advice would be to buy what you can afford and dont buy what you cant, this hobby is a luxury not a necessity. if ur a baller and CAN afford to buy the entire line to complete it then great, but if you cant (like most of us) then obviously you cant afford to be a completist, you live within ur means as with anything in life.
Should ask yourself what the point is to completing an entire line, do you absolutley feel that u need every character in that line to satisfy what you love about that movie or story? if not then just buy what you like to get that sense of fulfillment.
I have pondered completing an entire line but then i thought whats the point, a few key characters is all thats really needed to represent what i like about the movie, also thought about how the figures would appear when displayed and it occurred that if friends came to my house and saw my collection they would prob only recognize main key characters anyway,
if i was a completest the whole collection would look too much and messy, less is more i say, this completest mentality doesn't make sense to me and to go to the extent of either completing a line or not even collecting seems too extreme, good luck hope u figure this one out