Hi Robin
LogoBot is approx 80% developed in terms of hardware, software is barely started, but there is a huge amount of ref info online - so that shouldn't be an issue (esp. for a programming course!).
Kit cost is around £10, including batteries. You may want to tweak the spec level up a little to make the kits easier to assemble/more robust.
Happy to discuss requirements this evening if you can make it... it would be a great incentive to get the project complete! Jamie has also been working on an Arduino course which may complement what you're planning - I'm sure he'd be happy to discuss that as well.
thanks
Damian