Well, the PC-based DVRs we normally use run in the $2000-$4000 range
but I've recently been testing a
really nice little standalone unit. I'm not generally a fan of standalones because the ones I've used have all been seriously limited in features, performance and quality, but this one has really impressed me. The four-channel model goes for around $450 without hard drive, although you might want to consider an 8-channel if you plan to go to five or more cameras (BTW, the site linked to above is really good to buy from - tell them I sent you!).
Our go-to camera for most customers is the
CNB VCM-24VF - solid vandal-resistant dome, true day/night with excellent low-light performance, can be flush or surface mounted, and has 2.8-10.5mm lens that gives you a pretty good range to adjust view angle vs. level of detail. There's no such thing as a one-size-fits-all camera, but this one comes pretty close.
Four of those plus that DVR puts you a little over at $1110, but it's some really great gear that will serve well in the long run. Or start with only three cameras and
the 8-channel DVR at $570 (total of $1065), and you'll have lots of room to add more cameras later.