We found a gas station for sale that I was interested in purchasing, spoke with the listing broker for about 20 minutes, he was very friendly, he said he would send a prospectus the next day but I never received anything from him. It is now two weeks later and I have called and left a couple of messages and emailed him. Voicemail at one point was full, then it was open again. I was able to contact the owner and they said that they want an offer on the business before they provide any documentation. I stated that I was willing to sign an nda but not to make an offer at this point. Is it common practice to make an offer on a business before seeing any paperwork?