1) What does it mean by 'on offer'? Strategies can be put in place to increase the perceived quality of what you've got on offer. In this situation "on offer" means the product(s) or service(s) you have available for sale. 2) Nothing can replace the creative buzz you get off interacting with them, really exchanging ideas, it's only whether the price of that is worth it. In this situation get off means "receive" but the sentence is not well written grammatically or in its ability to convey meaning. "Get off" means receiving pleasure, often of a sexual nature. I would not recommend using it as this user has in what sounds like a business situation. "It's only whether the price of that is worth it" (and it should be a separate sentence) means "If the inconveniences of interacting with others is less than the benefits of the 'creative buzz' depends on the situation." 3)Is 'course' equal to 'of course' in the word meaning? In some ways, yes.., course, the question is, how do you get there? Yes, in this situation the writer is shortening "of course" to "course". This is not typical and looks sloppy. I presume all three of these interactions came through chat, forum or email? Please be aware that the grammar and word usage is quite poor throughout. This is not the type of writing to mimic.