Asked by child-priest.
I've actually never heard this belief before, but it sounds like a superstition similar to how you're not supposed to buy an opal for yourself.
The only times I didn't buy the deck for myself were: 1. When I was in 6th grade and my Dad said I had to get straight A's in order to get a tarot deck (my first deck, more on this in my blog post on which decks I own). 2. I received a Goddess Oracle deck for Yule a few years ago. 3. When I graduated college and my Mom found a super rare deck for me.
Every other deck I have chosen and bought for myself. I was traveling to Portland once and went a little overboard and I think I bought 7 decks in one day. In fact, the deck I use every day I bought for myself on KickStarter (I highly recommend looking for decks there).
I love my deck, It's always on my person, it lives in my purse. And I find that we connect spectacularly. In my opinion, as long as you connect with the deck there is no harm in buying it for yourself. Though, that doesn't mean I'm don't get decks for my friends. But that's only because I think they should have them.
I hope that answers your question,
P.S. Ask questions in the comments and I'll answer them in future posts.