Everything is relative.
Durons were always budget chips for lowcost machines. The main difference between Durons and Athlons is that Durons have much less level 2 cache onchip.
Since AMD came out with the Athlon XPs with "PR ratings" relative to the clock speed of the old socket A Athlons (and not the Pentium III and Pentium IV machines), it's all a bit confusing.
Durons run at their listed clockspeed. Thus a 1200 Duron runs at 1200 mhz.
Now, to put things in perspective, the Duron 1600 runs at 1600 mhz, will smoke anything named Celeron, will give the Pentium IV 1.8 a run for its money (beat it in most benchmarks) and is pretty close to the speed of a Athlon XP 1700+.
Budget now, but kickass a year ago, and still fast enough for anything you might want it for, unless you do music composition, compile Linux kernels for fun and profit, or crunch multimillion number datasets.
Right now, there's a roughly inverse relationship between clockspeed and value for $$$, so it really does not make sense to buy at the high end unles you want bragging rights or do specialized work.
Take the money you will save from buying a cheaper processor and use it to buy an extra 256 MB of DDR RAM, or a faster videocard.
