Can we get a trademark without a legal entity?

You can always apply for the mark - whether it is a Section 1(b) intent-to-use application or Section 1(a) in-use application - as an individual and assign the application or registration once you incorporate.

Trademark application filing fees generally start at $225/mark/class of goods. Prior to any filing or your use of a mark in connection with your goods, however, you should have a thorough trademark performed to ensure to are no conflicts. Costs associated with such a search, and with prosecuting the application, can vary depending on the mark in question.

A smooth trademark application process - strong mark, no conflicts, no opposition, etc - may require in the neighborhood of $600, excluding filing fees.

It is very advisable to review your branding strategy with a trademark attorney before purchasing domains, marketing materials, and filing state or federal trademark applications.