If you wanted to get two brushes to do all your work, why would you get an 0 and a 1? They're too close together in size. If he were getting just two brushes I'd suggest an 00 and a 4 and that way you've got a fine detail and a larger area brush. However to be honest if he thinks GW brushes are over-priced, Series 7 really isn't the way of the future.
As I say pretty much every time this discussion comes up, GW brushes tend not to be over priced, last well and have decent quality tips. If you're paying less you're usually going for a substandard quality, if you're paying more it's not worth it unless you take your painting very seriously and you're buying Series 7. Nose up the thread that I've merged with this and write down a few names and try to check them out next time you're in a hobby store - see what their bristles and their prices are like and make the decision based on your needs.
Topics merged, read the stickies.