There are different market segments in in the web design world. there are those that want to learn how to design something from scratch, and then there are those who want to learn enough to build upon the work of others (bootstrap, jQuery UI, etc.). I fall into the latter category, so I can't give any recommendation on the course structure or cost.
That said, there is a lot of buzz around bootstrap v2 now, so you might consider doing it the other way around - pick a few bootstrap customizations as a teaser class to help built market momentum for the full classes.
That said, there is a lot of buzz around bootstrap v2 now, so you might consider doing it the other way around - pick a few bootstrap customizations as a teaser class to help built market momentum for the full classes.