First of all, it's a very sad message, but I think all of us will understand this decission. I was an active member of the forum many years ago, bu now it's hard to find time and motivation to write posts. Many of us got married, have children and are busy with their daily tasks. The status of the team doesn't help either. On the other hand, I bet that many of us are still visiting the site every 1-2 days, but we are "invisible". rcdlc.com is still my only source of information about the team, and I'd still love to visit it regularly, even if Depor is suffering and every year is harder. Anyway, as I wrote earlier, I understand the decission and I can only thank all the people who spent years writing articles for the website.
Indeed, the cost of the server was huge! If we use a Polish one, I think we would pay yearly around 25€ for the server and another 20€ for the domain and that's all. If we'd like to keep existing model, maybe we could migrate the website to wordpress on a different server, but I guess it would not include all the existing articles as it would be too hard to do. We would just start a brand new site with the same address, but with a new, modern layout. I have no idea about the forum. Maybe comments under articles in wordpress would be enough for us to keep the discussion. This solution would be quite easy to implement.
I don't know reddit. I know it exists, but I even don't know that is the role of this service. I think it might be not too popular, but I may be wrong.
Changing the model for Facebook would be fine, but not all of us have FB, so they will lose the possibility to read and comment the articles.