Be aware the RB Auto Graflex was also made in 3 1/4 X 4 1/4 film size, so it is worth measuring to be sure, if you intend to shoot with the camera. Being able to use 4X5 film directly out of the box is a lot handier than cutting 4X5 down to 3X4. Also most Graflex cameras use special film holders that are slotted along the two long edges. You can't use standard sheet film holders. If there are any slotted Graflex holders in this collection you want to get them. Holders can be found on eBay, but aren't common. The RB Auto is a nice camera if you wish to use longer focal length lenses since it has a long bellows draw.
If film cost for 5X7 or 8X10 is an issue, some people are using X-ray film cut down to size, or even make paper negatives from B&W printing paper. Both of those have drawbacks, but may be worth it for the cost saving. You can do a Google search for details on both methods.
The Graflex shown in your fourth picture looks to me like it is possibly a Home Portrait. If it a 5X7, has a revolving back, and front tilt movement, it is a Home Portrait. This is a rather rare and sought after Graflex. I don't follow Graflex prices very closely on eBay anymore so my guess of a value around $400 to $600 may not be really accurate, but it isn't a $150-200 Graflex either. Shutterfinger may have a better idea on value.
Len