A blank drive should be all you need. We still recommend you buy a +/- drive, as a standard still hasn't surfaced. Also, DVD blanks have become cheaper, but are still a lot more expensive per Mb than blank CD.
The prices of DVD burners are falling like a rock, and with the recent introduction of dual-layer DVD burners they will continue to fall. I've seen some sources claim that by early fall of this year, some 4X DVD burners will be less than $20, while 8X will be under $40.