For me an option that is doubtful, don't be too hasty. Now try to buy Tron tokens first and send them to your TronLink wallet. I don't think it's necessary to buy in bulk first, and just buy on a trusted exchange like Binance with a transaction fee of 1 Tron, because Tron is also available on BSC, Ethereum and other better networks.
Same with other netwoks, he will has to deposit some eth to cover the send fee (for ethereum network) or bnb for Binance Smart Chain network. By using exchanges to store usdt (or any other token), the fee can be deducted from the token itself (some exchanges offer more options), but it's not recommended to use exchange wallets for cold storage.