if you want cheap, you can try those from community centres. But well not sure about their teachers.
Harbour Dance downtown is another place you can do drop-ins for Jazz and Hip Hop.
I just went to harbour's website and was surprised that I still recongize some names. Their drop-in without membership is $17 for 1.5hr class and $13 for 1hr. Try it and the punch card is a better deal if you continue to take classes there.
For Hip Hop Intro (assume that you never taken dance classes before, intro is the lowest level), I think Kim Sato's class is easier to "get". But other teachers may be as good as well. They used to let ppl watch part of the class so you may try to watch one before you decide to drop in. And guess u can do the same for Jazz intro.