It may be somewhat run down, but I wouldn't describe the buildings pictured as being "ruins". It's got a roof, windows, reasonably well kept landscaping...
Based on German reports...no significant renovation since being built...so thats why the price was so low. You can anticipate the cost of renovation being in the tens of millions of dollars. The negative side is that summer barely last six weeks up in the Baltic area...maybe 12 if you are aren't picky about weather. Its hard to say if this guy can ever turn this into a profit-type hotel.
An interesting note...there are 1000s of structures (not quiet as grand as this one)...that lay abandoned in Germany. From old hunting lodges, to old train stations, to old businesses. The German rail system probably has over 500 structures just sitting there...with no one interested. Face it...who wants a old train station?