http://finance.yahoo.com/q/pi?s=DODFX list major brokers who sells DODFX.

Usually, there will be a transaction fee of 35$ for fund purchase and sell, unless you purchaes it directly from the fund's issuing company.

Or, you can check out https://www.firstrade.com/en_us/home.htm, they do not charge the transaction fee for many funds.

For the ETFs, they are traded just like stocks, and will always have trading fee (transaction fee), the same amount as stocks. So any broker can trade them.