In a note to clients — as reported by “Barron’s” (http://macte.ch/mYO9R) — Ticonderoga Securities analyst Brian White reiterated a “buy” rating on Apple shares and an US$550 price target.

He notes that Apple’s shares, backing out $64 in cash per share, trade at just 11 times his pro-forma EPS [earnings per share] number for calendar 2011 of $25.58 this year, and just 10 times his 2012 estimate of $27.75. White says Apple may increase prof-forma earnings 37% this calendar year, but the S&P 500, which is projected to increase EPS only 11%, trades higher, at 14 times.

What’s more, the analyst thinks estimates are “conservative” given continued strength in Apple’s product line. He estimates cash will increase from $60 billion, roughly, at present, to $74 billion at the end of the September fiscal year, and $126 billion by September of 2013.