Best value method for trading BTC into BCH and altcoins?

[Clear and Focused]

If someone wants to trade BTC into BCH + maybe 2 alt-coins - we're talking small amounts here ~$2000-3000 worth of BTC, what is the cheapest way? In my limited estimation, I would normally do this with Changelly so that I only have one transaction each, rather than transferring to an exchange, then trading, then transferring off the exchange = at least three transactions. Is this changelly route truly the cheapest or am I missing a better solution?

Thank you in advance