I came across an article about sprouting and I found it interesting and decided to give it a try. I bought specialized sprouting seeds and my girlfriend asked me why I was buying such seeds when she could just get much more beans for cheaper at grocery store and make them germinate. She actually challenged me and bought a package of beans and she's going to grow them... I didn't know what to reply to her! Is she right? What advantages have those seeds over what you can get in grocery store? Are they as nutritious?
There may be various factors that affect the germination of the seeds:
-Firstly there is the possibility that supermarket seeds are contaminated, or have been through chemical treatment. This may affect germination or plant growth.
-Secondly there is the problem that you would not know the exact cultivar(type of bean) of bean you would be growing in many cases.
-Third and finally, the special sprouting beans most likely are a special cultivar that sprouts at an accelerated rate, or having certain advantages over the regular store-bought bean varieties (such as nutritional values, growth rate, size etc.)
I am no bean expert :P, however these are just some of the most logical arguments that I could come up with to justify your special beans.