I'm a web designer and personally I don't think TS should spend too much on learning design and digital illustration. At the end of the day, it is the passion and self motivation that allow use to create better artwork. Cert play minimal role and portfolio do the talking . 50K to study illustration and it might not contribute to your income... IMO it is not worth it.

Another reason is that web knowledge expired fast and there are a lot to learn. Put visual sense and interface design aside, the codings like HTML, CSS, Java Script, Action Scripts 2.0 3.0 evolve like crazy. As a web designer we cannot say "No, I don't care about technical, it is not my area". The moment you graduate from your school the knowledge is half-expired. Reminds me that MMU teached me Macromedia Director & Freehand and that's the time adobe stop releasing new version. Luckily that I self learn Macromedia Flash back then.