VSAT is definately not a solution for PTZ cameras (latency). 5GHz point to point is generally the way to go, which may result in a few repeater sites to get line of site to the cameras. This all depends on whether you have access to power poles or other locations along the route. With Ubiquiti NSM5-US ($75 each) you can accomplish this. If you only have access to the headend site and the camera sites, you would need a longer wavelength, like 2.4 GHz, to get through the obstructions, using a multipoint or PTP scenario. It is not stated where this is located, so in urban areas, interference can be an issue using 2.4 GHz (WIFI). For 25K, I also did not see you state how many cameras were to be deployed.
Using 5GHz PTP, I have been quoting probably an average of 4-5K per HD ptz camera (cities install the power harness that I give them to the utility poles). I would expect a repeater pole (two radios, no camera) would be about 1-2K (mostly labor and lift charges on this). Ubiquiti is neat because it has a second NIC port with POE out, eliminating the need for a switch. I have gone out to 5 links using this method with no loss of frames or video from 1.3 MP 15fps PTZ cameras. You need to be aware to program dedicated frequencies for these links using declining bands (for example, 40 MHz first link, followed by 20 MHz links in 5.8 or 5.3 GHz links, with maybe 10 MHz bands for final legs). Look at the spectrum and provide at least 5 MHz separation between bands (for example, using 5765/20, this would occupy 5755-5775, so the next band may be 5785-5805). Do a frequency map/plan on this. You can reuse frequencies as long as they are not line of site to another link that may cause interference. Do not just use "auto" mode on the radios.
Pull up a Google earth shot of the area and camera locations, and see if you can "line of site" your way to the cameras. Include repeater sites where needed, (as long as you can get access to the site).
You could also try 900 MHz, which will work non-line of site, but bandwidth is limited as is quality of service, which may/will interupt a H.264 video stream. (You could do a combination of 900, 2.4, and 5 though with proper planning).