Very interesting topic.
I agree with Goose about the importance of the first interpretation you have listened to. It usually (not allways, tough) happens that it is the one i prefer.
For instance, lets take Chopin's Fantasie Impromptu.
The first version i have listened to is by Anatol Ugorski.
Later, i bought Cds with Cziffra and Arrau playing it. Everybody should agree that both are better pianists than Ugorski, but the fact is that, among the 3 interpretations, i still prefer Ugorski's.
In what respect to own many recordings, i usually prefer to enlarge my collection with new works to make it more complete. For instance, i adore Chopin's Nocturnes (i have Arrau set), but instead of buying another set, i prefer to complete my Chopin Music.
The same happens with Beethoven sonatas. I do not own a complete set, but i have right now 22 of them, by several pianists (Gulda, Kempff, Jando, Kovacevich, Barenboim, Richter). Instead of buying new versions of the well known ones i already have, i prefer to complete the 32, even if they are the less known ones.
As a side note, this is completely unrelated to my beginner repertoire, that currently consists of:
Fur Elise (easy part)
Tambourin (Daquin)
Many Czerny, Beyer, etc
