
Matt G. answered 05/29/19
Your Coach for Success!!
Ending a sentence or phrase with "with less" but without stating the object is a common way to simplify the idea in English. In fact, according to Google Ngrams, it is more common in publications to end a sentence with "with less" than to use "with less money." You will also find it used in spoken speech on TV shows. For example, "I'm sure a lot of great people have started with less" (Simpsons, 2004, found on https://www.english-corpora.org/tv/).
As far as using "less" versus "little," less is the right choice. It this situation, you are comparing the amount of money they would need to spend doing your suggested method to the amount they would otherwise spend if they weren't following your method. Since "less" is the comparative form; therefore, less is the correct choice.