You can buy 1000' rolls of Direct Burial Siamese cable from SYstek for $275/1000. I have been told that you can run TVI out 1500' on that cable but you need to use 24 volt (24v-12v) cameras. Since you have the dvr already, just buy the cable, do the splice and bench test it at the dvr with the cables still on their spool. That way you will know for sure. If you have problems you can always downgrade that location to a 760 analog 24v camera. If voltage drop is an issue and you have 120 volts available near the camera you can put a transformer out near the camera to supply either 12v or 24v.
We own two self storage facilities with out buildings 700' away, so we have had to get creative at those remote locations.