Is it true that withdrawals cost about 20$?
Depends on current rate. On HitBTC withdrawals cost 19EVN which is currently about 15$, but it already was more than 20$
Soon it will be on other exchange too with lower withdrawal fee that is bad action from Hitbtc which made it dislike. If they could resolve this issue and make it at realistic level than it will grow more strong and could become the top exchange.