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Jason Lthat is what gives you the most joy!
There is little sense in collecting things that don't do anything for you, or that you no longer look at, etc.
Matty is a tough choice, from a cost perspective, so you just need to be realistic about what you can afford, and if you can get far enough so as to not frustrate you.
And hey, it's better than picking Honus Wagner, as I understand he has one card in particular that is rather tough! 
Good luck with it, whatever you decide.
If you don't mind me asking, why Matty? any interesting collecting stories regarding him?