I recently went through a search for German courses in Basel and would be happy to share with you what I learned.
Perhaps the best place to start is by looking through the list published by GGG called "Deutsch in der Region Basel". It's a handy flier that lists and provides information for 20 different language schools in the area. You can find a pdf version here: http://www.integration-bsbl.ch/deutschkurse/
Below is a list of some of the best deals
in town for language courses that I could find. They are listed according to price per course hour, certainly one of the most important factors in my consideration.
(I should also mention that I was looking specifically for intermediate level courses. Some places seem to offer particularly good deals if you are a true beginner. Also, if you have a student visa you may qualify for further price reductions.)
Good luck in your search!
- Jason Allgemeine Gewerbeschule http://www.agsbs.ch/ausbildung/weite...fur-erwachsene
Kleinbasel, by Messeplatz
[Update: it's 200chf per 1.5 hours/week course. I don't understand yet how one can take more than 1.5 hours/week. Either way, it's cheap and could be cool if you live in Kleinbasel.]
5 month semesters (Jan-June & Aug-Jan)
200CHF or 400 CHF!!
5.3chf/hr Auslšnderdienst Baselland
Pratteln! (35 minutes each way from Marktplatz)
3 month courses
One or two lessons per week.
Mornings or afternoons
5 month semesters (Jan-June & Aug-Jan), 17 weeks
220 CHF or 440 CHF, depending on once or twice per week.
~8 week courses
16.0 chf/hour Volkshochschule http://www.vhsbb.ch/s_deutsch_e.aspx?pos=81
Evening classes, twice per week
8 week courses
[As a point of comparison, Benedict-Schule Basel that you mentioned offers a variety of courses, but the average intensive course would amount to approx. 30chf per instructional hour.]