I recently bought some Hikvision dome cameras, and they seem to be worth the money so far. For the cheapest option with decent quality, I recommend the 4mp DS-2CD2345G0P-I (turret) and DS-2CD1143G0-I (dome). The turret one is around $100 USD, and the dome one is around $70 USD. However, make sure to buy from reliable suppliers. I used to purchase Hikvision and Dahua cameras from some suppliers, but they turned out to be Chinese versions. After trying a few suppliers, I found one that offers overseas upgradeable versions at competitive prices. DM me if you want the contact info