I would never say never or even don't do it, but you've got to do it for the right reasons.
I would say the web design market is saturated. It's a tough market and there are some atrocious websites out there that people have paid for. It makes me weep. Realistically it's too easy to design a bad site, even one that is database driven. Cheap hosting and template packages can have anyone throw a web site together in minutes. You'll have to have the edge. For the 30k mark, I would expect decent resilient design, web logging and trend analysis, full disabled accessibility and web compliance, database creation and maintenance, modest knowledge hardware/hosting provider selection and a knowledge or a variety of coding tools. PHP, JavaScript, C#, VB.net etc.
Networking is a tough market too. At the lower levels, plugging PC's into a hub and clicking a few things on a server to manage accounts isn't difficult. It's all the background infrastructure, resilience, logging and preventing downtime which you'd need to start learning about. Different cabling, connecting various offices together, backbone Internet line, backup, remote working etc.
The adverts on the TV don't help either suggesting that you could earn shed loads in IT. Some people do, some don't.
I am a web programmer / system developer. I'm 28.
Follow your dream though... I hope the above helps a bit.