Hi,
I know this is an old topic but it's one that just on keeps on coming up.
I worked at Lagan College for many years but now I'm the other side of the fence. I created the
http://freeperiod.co.uk room booking system about 9yrs ago. My site is used all over the UK and around the world now.
I guess I made it knowing exactly what school's need. I also worked hard to keep it simple. You guys like me probably love making stuff and getting your hands dirty with open source stuff and web/database servers. This can come back to bite you at some point though in terms of workload.
When someone asks the question is a room booking system worth ?300 your gut reaction is to say no. If I was to ask would you do 100hrs of work for ?300 you'd definitely say no. One of my skills is doing the least work required. So maybe we should think in terms of your time and effort when looking into new systems. We'll not even get into what happens to the system deployed when you, the clever one, leaves the school

Cheers,
Chris