Yes was always about the €500 mark, but IMHO most I came across never did a very good job, only a few were up to the mark on flushing.
System should be drained, cleanser added and allowed circulate in the system for at least a week (up to a month) , most I came across turned up and completed flushing in one day with no previous visit. (unless they were using something like ds40, but pretty aggressive stuff!)