how to make a chandelier the barter dilemma... how to handle it correctly ...

Hi all, I read an article about a warrior member a few days ago and he got the whole "marriage pack" in exchange for various IM missions.So, in these days, I think barter trading may be a great way for offline business.But..Now I have two questions: 1) First of all, you have to take things away at a gross or net price?I mean, I developed a website for $400.Merchants sell a TV color for $400, the net price of $300.So do I have to bring only the TV color, or does the TV color add $100?I think the correct answer is the second one, but I don't know if the merchant will agree with this exchange..2) after that, I think this merchant may have some problems with the tax bureau.How to deal with this "donation "?Hope someone can give me some answers!Thank you guys!