On this I found web site, in the extra information, it says the first Mac sold for 666 dollars. So would it be bad to buy Apple products because that number is the sign of the devil or something? I don't know exactly why the number was bad, but I remember the Bible said it was bad. Then it also says when people asked Steve Jobs why he chose that number (the sign of the devil or whatever it is) he just said he took a lucky number and subtracted 1. First of all I know luck isn't true. I didn't even know some people thought seven was a lucky number. I don't know if he was telling the truth but, beside that, since it was sold for 666 would it be bad to buy Apple products?
These innuendos are there because Jobs and Apple were successful. The charges have no biblical basis. They are made by people who are jealous of other people's success.
You said 666 represented unfinished or fully sinful and that simple meanings are over-thought sometimes. The Bible says that great wisdom is needed to interpret the number 666.
Actually, the verse says, "Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man: His number is six hundred and sixty-six" (Revelation 13:18). What John is saying is that you have to think about it for a bit. The number isn't arbitrary, but selected purposely.
Seven is the number for complete perfection. Six then becomes something not complete, or less than perfect. Three of something is repeated for extra emphasis, like underlining, writing in bold, with exclamations. It is also the number for something completely represented. So 666 represents the beast: a complete, emphatic representation of something that is less than perfect, or fully sinful.
Actually the claim about the price is false anyway: "The first Apple Computer called the Apple I went on sale in July 1976 for a retail price of $666.66. Some say the price was chosen because of the repeating digits but in reality, the first 50 computers were originally sold to the Byte Shop for $500, who then added a one-third markup to the price." [Answers.com] So, however you look at it the price wasn't 666.
I've heard that the bite in the Apple logo represents the bite Adam and Eve took out of the tree of knowledge of good and evil and at the same time sinned. So does this mean that Apple products would be bad because they have a representation of sin in their logo?
What you are getting into is a form of gossiping. People have the tendency to believe the worse of others, especially if the other person is successful. "An ungodly man digs up evil, and it is on his lips like a burning fire. A perverse man sows strife, and a whisperer separates the best of friends" (Proverbs 16:27-28). What you have found are web sites of this nature. They claim to see evil in the most mundane things.
I dug around for the facts behind the Apple logo. When Apple first started in the 1970's they went through a series of logos. One of the earlier ones was:
Prior to the first Macintosh, Apple used a typeface called Motter Tektura alongside the Apple logo, which was designed in Austria by Othmar Motter of Vorarlberger Graphik in 1975. ... According to the logo designer, Rob Janoff, the typeface was selected for its playful qualities and techno look, in line with Apple's mission statement of making high technology accessible to anyone. Janoff designed the logo in 1976 while working with Palo Alto marketer Regis McKenna. The Apple logo’s bite mark was originally designed to fit snugly with the Motter Tektura "a." [http://en.wikipedia.org/wiki/Typography_of_Apple_Inc].
In an interview, the designer, Rob Janoff, said, "Anyway, when I explain the real reason why I did the bite it's kind of a let down. But I'll tell you. I designed it with a bite for scale, so people get that it was an apple not a cherry. Also it was kind of iconic about taking a bite out of an apple. Something that everyone can experience. It goes across cultures. If anybody ever had an apple he probably bitten into it and that's what you get. It was after I designed it, that my creative director told me: "Well you know, there is a computer term called byte". And I was like: "You're kidding!" So, it was like perfect, but it was coincidental that it was also a computer term" [http://creativebits.org/interview/interview_rob_janoff_designer_apple_logo].
People have ascribed "meaning" to the logo after the fact, but truth is much simpler.