Several things I want to add to the discussion, which some have already touched on:
1) AAPL current stock price is still considered "cheap" for how much the company has in cash and cash flows. any intro to finance course will show how this is calculated. don't let a high stock price fool you into thinking "it's going to crash back down, it's too high!". if AAPL feels its stock price is too high, they will do a stock split - which will be highly unlikely at this point
This is incorrect by most fundamentals (not "technical analysis" measures, which are anything but technical or analysis in the financial sense).
How most M&A consultants do a business valuation, which is what the institutional investors would pay if they wanted to shrewdly acquire a stake... and what a shrewd investor has to compete with if you don't want to be left holding the bag, it's a triangulation of three factors:
1. Comparable industry P/E multiples
2. Net working capital (current assets minus current liabilities) plus projected operating cash flows (discounted to net present value)
3. Extrinsic factors (e.g. currency risk exposure)
Personally, I ignore P/E multiples because all they tell you is how many times over actual earnings the market was dumb enough to pay for a stock on the supposed basis of future speculation. But a shrewd investor always concentrates on what the stock is worth right now. There are two key measures for this: 1) Tangible book value and 2) Intrinsic value. The former is inarguable, but the second has a few basic approaches.... I tend to stick to the valuation method embraced by Buffett and other value investors.
Apple is currently trading at about 5.8 times its tangible book value. A good baseline comparison is the Price to Book ratio of the S&P, which is about 2.36. While AAPL has had higher one year growth than the S&P, the S&P has more room for overall growth than AAPL because the overall index is still not as overpriced relative to book as Apple is and there's significant growth opportunity for other companies in the index that aren't yet as proliferated in their respective markets as Apple is.
Regarding intrinsic value, I made a recent calculation that placed Apple's intrinsic value (while Steve Jobs was still around), at $100 per share below their current market price. Note that I didn't include anything like a "Steve Jobs factor" in my intrinsic calculations because I don't care what the market overprices the asset to.... I care what that asset is worth to me right now, so I can profit off the difference rather than be swept up by the market.
The reason I stick with operating cash and net working capital is this: The number of gold toilets at Apple HQ has no bearing on their ability to generate cash from their primary business. The cash from financing activities can be manipulated. But operating cash ticks and ties to how good they are at the thing they do that makes them uniquely Apple, and net working capital (current assets minus current liabilities and intangibles, e.g. good will--a measure of the excess over carrying value paid for an asset) is the engine that generates the operating cash. So to me, these are the only items on the books that really matter, not including accounting irregularities (which are easy to spot if you read the annual reports from back to front).
Extrinsic factors are harder to target and I just try to keep it simple by investing in companies that aren't exposed to tremendous currency risk, that aren't ADR's, and whose business I can easily understand. Manufacturers are easy because their working capital (inventories) tick and tie to their sales. Banks are nearly impossible because if you can find anyone who clearly understands what Level 3 assets are really worth, that person should be President of the Universe.
Apple is not a "cheap" stock and I have picked far more discounted securities that match the gains I would have had on Apple in the past year without the risk. That's not to say you would pick a lot of them, but overall you're not going to find many Apples in your life. Get used to the idea... and heed the words of Ben Graham who has been right decade after decade about the difference between investing and speculating:
An investment operation is one which, upon thorough analysis, promises safety of principal and an adequate return. Operations not meeting these requirements are speculative.
The only other thing required is unswerving patience. Over time, you'll compound far greater gains by investing shrewdly and consistently, than you will by speculating wildly, betting the farm where everyone else is and exposing yourself to risk because any number times zero is still zero. Remember Steve Jobs' favorite quote from Wayne Gretzsky: "Skate to where the puck is going to be."