If 500 Startups funds a company ($50,000) to join the accelerator, it will charge fees to help cover the costs of running the accelerator office space.
It keeps the company in check. It reminds the company that expenses come with the business. It forces founders to be mindful of what they're getting. It makes everyone realize that they're being invested in as much as they're investing too.
I don't care if psychologically $35k sounds better than $50k minus expenses to you. It makes for better founders and better companies. You should think about it from this perspective.
If 500 Startups funds a company ($50,000) to join the accelerator, it will charge fees to help cover the costs of running the accelerator office space.