I've sorta been "rolling my own" systems for friends and family to fit their budgets. They are all IP camera setups, but I've been running Amcrest NVRs and Amcrest ProHD cameras with good success (for close to 5 years now)
Realistically the NVRs aren't anything to write home about. Mine don't seem to like streaming 8 channels of HD at the same time, but realistically I don't watch it like that. I setup some motion detection and let it alert me of any issues. If I'm streaming, it's typically 1 or 2 channels at a time and only for a short period of time. UPS man pulls up to the driveway, I'm not watching the monitor all day, I just get an email alert.
However, I've seen some terrible reviews on all of the budget systems, so your mileage may vary.
Buddy of mine bought an off the shelf NightOwl system, however he complained about the night-time cameras weren't really good at night, too dark.