I have SmartChain BNB in my Trustwallet (TW) account.

1. Is it possible to buy ETH-based crypto on TW with SmartChain BNB. If yes, then please inform me how.
2. As I am a newbie, I want to buy ETH-based crypto for only $5.1 amount. Will it be cost-effective, as many people are saying cost will be high on ETH transactions? So I don't end up with like paying $5.1 for buying and paying $2 or $3 for transaction fees.

By the way, I want to buy DEUS FINANCE. It is also on POLYGON Chain
https://coinmarketcap.com/currencies/deus-finance-2/

Please guide.