Just to add to answer number 1: I'm not sure why the word "figure" was used in this context, since the term "model figure" is usually used to either refer to a person who has admirable or exceptional qualities worth copying (or emulating), or to describe the ('perfect') shape of a woman's body. Otherwise, the word 'model' can be used as an adjective to describe something that is a kind of prototype, or something that is built for demonstration--model car, model house, model computer, and so on.

1) Model figure - in this sentence, 'model figure' means the computer was not a real version of the product your friend was intending to buy. It doesn't literally mean 'fake', but in this sentence, the word 'fake' would make sense there. 2) 'You' has been used here to mean anyone who opened the computer, not specifically the friend - it means 'you' generally, like a plural. 3) You're right - 'straight-up' is something like completely. In this sentence, the meaning of it makes sense as 'completely'. I hope this answer helps you :)