The software is the same, the only difference is the licensing, SBE has some thing disable that EE does have enable.
You can read the attached document with the things that SBE are included, see pg 16.
Now about the prices, you can check the following link QlikView Business Intelligence Software Pricing, Bi Platform | Qlik and/or speak with you Qlik sales representative.
LicenseTechnicalDoc_A4.pdf 1.5 MB
technically speaking, there is no difference between the Small Business and Enterprise installer. What makes the difference is what your LEF says. The License Enable File is what like it's name says, enables or disables some features depending on what you purchase. I'm attaching an image with the main differences between every server versions:
* EE = Enterprise Edition, SBE = Small Business Edition IAS, = Information Access Server QES = Extranet Server