Buying 30 different coins one by one is costly due to transaction fees, so investing in one coin that does this for me seems cheaper.
Hmm. I do not think that backing assets will be bought for each coin separately. Most likely, it will be provided by the creation of a pool of coins, or some stock of backing assets.
In addition, buying and selling will be carried out on exchanges, therefore, it will not be a transaction fee, but an exchange fee.
But the question is really good! Let's wait for a response from Don.
Paying 0.25% exchange fee on 10 USD at once or over 30 transactions of 0.33 will result in the same fee at the end.
The bigger Issue is that it takes a lot of time and effort to be able to buy the top 30. Multiple wallet, multiple exchanges. With CombiCoin is just 1 transaction, 1 wallet, 1 exchange.