We are trying to figure out what portion of the capital raise will go to the bankers.
Many startups complete Series A funding rounds without engaging investment bankers (typically advisors are used when much larger amounts of capital are involved). That said, there are boutique advisory firms that take on smaller capital raises as would normally be the case with a Series A round. Fees for smaller capital raises usually range from 5% - 10% of the capital raise (see the source link below for lots of detail on the formulas traditionally used by bankers to set fees based on different sizes of deals). Some firms may require a retainer fee that is usually deducted from the success fee once the capital raise is completed.