IMHO, i think this still cheap providing there are A LOT of html tutorials out there.. why not develop it and make it unique? like an interactive html tutorial.. or a 'test your html skills' type of website.. you could reap hundreds if you develop the domain..
low $xx to mid $xx undeveloped
high $xx to high/mid $xxx developed
providing you stay with the site for 3-5 years with good SEO and publicity, you could make it to thousands $..
thank you.
=)