No walk through until contract is executed?

[Robby Sanchez]

I have a deal I'm interested in and would like to know more about it but the broker specifically says "there can be no showings until a contract is executed" what exactly does that mean? I understand I have to submit an offer before I can see the property but How am I supposed to come up with an accurate purchase price if I don't even know what the insides of the units/amenities look like? Do I just submit an offer based on the information/pictures provided and then retrade if there's things that come up during the due diligence period after I have already submitted the offer? 

thanks everyone!