I've never actually seen a contract but I have heard that a basic Weider contract started at approximately $40,000 per year. Once the athlete was signed and under wraps, he/she was obligated to the terms of the contract plus a predetermined number of guest appearances each year.
Some of the more knowledgeable NPC promoters would contact Lynn Conkrite (spelling?) at the Weider office and work out a deal to have the Weider name on the poster in exchange for one or two or more IFBB pros to participate as guest posers, thereby saving a couple of thousand on each guest that participated.
If I recall right, the promoter had to pay for the travel expenses and hotel and meals but the basis guest posing fee was covered by Weider. At that time the basis fee was about $2,000 so it represented a considerable savings for the knowledgeable promoter.
In almost all cases the pros would also set up a booth at the event and sell photos, lifting belts, etc. and return home with an additional couple of thousand for their efforts.
Andreas Cahling appeared to have the most organized business selling posing trunks, photos, and belts and I think he still sets up at various BB events throughout the US.