If you are capable of buying altcoins with your fiats then I will suggest you to go for it as it will be saving some commissions. But I'm not sure that you are already aware of the process of depositing fiats into crypto currency exchanges to buy those altcoins. But, you can find local sellers also for these coins to buy from them.

But usually people who are trading/saving altcoins, buying them with bitcoins as they are already having bitcoins ready for their purposes. But going straight would be the right approach if you ask me.