It's always a good idea to get the best iron you can afford. If being used a lot they are more of an investment than anything really.
I've been through various mains powered irons and a couple of stations. Currently using a Weller WD1000 setup that is the best I've had by far. The only better equipment I've had the pleasure of using was at uni while doing my degree in electronic engineering, but they were £500+ irons. The Weller isn't cheap though and still cost around £300, but like I said, if you do LOTS of soldering day in day out like I do it's worth the money.
Thanks alot for this post I was gonna post a thread about this! I have a 30 watt prcaticing how to solder.. using no clean solder it sucks.. trying to know how to tin points.. getting the hang of it.. been 3 days after reciving the nand x kit not ready yet haha