Looking for a cheap apartment for rent in Union County, NJ? With RENTCafé, finding an affordable apartment in Union County, NJ has never been easier. We feature 38 low-priced rentals directly from property managers, with rents lower than the Union County, NJ average. What is a cheap rent in Union County, NJ? The average apartment rent in Union County is $1,573 per month so any rental south of $1,258 would be considered cheap here. Size matters though, so if you are in a market for a studio, expect to pay around $683 per month. If you’re looking to upgrade to a 1-bedroom apartment you’ll pay around $949, while a cheap 2-bedroom apartment will cost you about $1,298 per month. On RENTCafé, Union County, NJ rents go as low as $1,437/mo.