That depends on your calling volume. Lidl and Lyca both charge € 0.09/min for domestic calls, which you can get cheaper from other prepaid providers such as
http://www.galeria-mobil.de/ who offer domestic calls for € 0.05/min but charge € 0.10 per domestic SMS and € 0.49/min for calls to the rest of Europe.
Lyca also offer a flatrate for unlimited domestic calls and SMS for € 19.90 and they also have the "Super Saver Flat" which includes unlimited calls to Hungary and several other countries, unlimited calls and SMS to Germany and 500MB for € 39.90.
It all depends on your amount of usage and your individual distribution of calls, SMS and data.