River found it hard to believe that such a good deal would fall into their laps, but no matter how he looked into it, Albert seemed to be legitimately interested in forming a connection. At the same time, he seemed to be a legitimate businessman.
The reason for calling them over in such a way was because while Albert claimed that he would have no problem delivering goods to their inn, strictly speaking he was not allowed to do that. After all, any goods he moved in and out of the city were supposed to be to fulfil the city's demands. But Albert assured River that instead of taking anything out of the official goods being moved out of the city, he'd just send along the supplies to be delivered to the Guest House.
To assure River that he was acting in good faith, he did not take any money for all the supplies River requested, and told them to pay upon delivery. It sounded too good to be true, but since he wasn't really losing anything, he went along with it.
