should I get engine rebuiltif so where or try to sell

What is your question?

ml 350 2006 1st told need balance shaft and timing belt; spark plugs then told 4 days later #3 &4 in engine no compression.MB will not cover 100k miles and paid for I don't know where to even start to decide how to get repaired -rebuilt engines 5k but should I and by whom. can't afford dealer. please help