I haven't money to purchase new unique articles for my website for now. One guy offers me to use a few articles writen by him. However these ones have been published at his own website. I'm afraid my website will be banned by google if I do use his articles. Should I use them or it's a bad idea I'm waiting for your advinces.
Well modify the articles a bit and use some more keywords related to your site. Definitely this will work
Your website definitely wont get banned for using duplicate content. You might find it more difficult to rank (although it's still possible). Unique content is definitely best though.
It says here that you write quality articles on Russian. PM me if you’re interested. why not make a trade with someone for some fresh content. then you have no worries about what Google thinks.
You can use duplicate articles, it's what thousand of people do on article submitting sites. It is better to write new ones though which have correct keywords related to your site.
It's always good practice to write relevant, new and interesting content to your users. This is what they want and this is the group Google want to keep happy. If you take the time to get good, fresh and useful articles - it should pay you dividends later on. There are no shortcuts to new traffic.