These Rollei TLRs aged between 20 to 90 years old. Market price depends heavily on its production quantity and conditions. Generally speaking, the 2.8 versions are much more expensive than 3.5 versions. Rolleiflex models are generally more expensive than Rolleicord models.
you may find a priceguide at antiquecameras.net
I will update my own price guide here in a few days – only about the popular models.