There is, in theory, no limit to how high in price any stock may go. Price alone is not a determining factor in the future price of any stock. Look at Berkshire Hathaway, it has gone from $7225 in February 1990 to over $130,150 today, an annualized rate of return of 13.6%.
For me the question is how long Apple can continue to grow its earnings at 20% plus, thereby deserving higher stock prices in the future? Currently according to http://finance.yahoo.com/q/ae?s=AAPL+Analyst+Estimates Apple is expected to grow its earnings at a rate of 22.52% per year for the next 5 years.
If this holds true, Apple stock shares should be substantially higher than they are today. I am currently a buyer of Apple as well as some other stocks. You may see the stocks I currently recommend at http://davesfavs.com/ for free, just use free as the user id and markets as the password.
The current mean price target for Apple is $736.17 for the 55 professional analysts that follow the stock.
I hope this helps Josh, Dave