Generally speaking, look for H67 and H77 motherboards, or if you intend to overlock (you have a CPU that can overclock), then looks for Z68 or Z77 motherboards.
Impractical to give you specific choices for cheapest motherboards because anything you get will be used and what's available and what the price is will vary wildly.
Unfortunately, $20-$30 is going to require a lot of luck and time in finding such a motherboard. This is very old technology and secondary sources like eBay are no longer flooded with Sandy Bridge/Ivy Bridge motherboards like they were in the 2015-2017 time period. $50-$60 is a more realistic budget, especially if you want something that will let you get the most out of your 2500K.