Even higher priced wireless cams are hit or miss. The entry level wireless stuff is garbage. Go wired if you can. Swann is good for entry level equipment. Their DVRs work fine and the cams are serviceable. They also have pretty good customer support if needed. Be aware that outdoor cameras do have a lifespan of 1-3 years average (unless you live in a stable climate), indoors are indefinite barring electrical damage of some kind. Depending on how many cameras you had in mind, $750 is a reasonable budget. You might also check out Everfocus, a bit more expensive but better quality than Swann.
1 to 3 years. Dang!