USB to RS485

Hi, I need to make a USB to RS485 converter. Whats the best way to do it? I know FTDI make USB to serial chips and i could use one of those with a MAX485 but is there a better way? Possibly a 1 chip solution.

Cost is quite important here. I dont mind paying a little extra for a chip that can output directly to RS485 because the MAX485 chips are quite expensive. If those chips dont exist then i can use a USB to serial chip with a MAX485 but which USB to serial chip would i choose? Im also after something i can get in a DIP package. FTDI's chips all seem to be those QFN type things.