It is very doubtful that there are any "cheap" replacement options for your motherboard. New options are going to be very expensive because that platform is many years past being current and used options are probably risky because you don't really know what you are getting.
As you can see here, there are barely ANY options anymore for new replacement boards.
https://pcpartpicker.com/products/motherboard/#c=101&sort=price&page=1
And what there are are very expensive.
And used, well, it's like rolling the dice.
Finding an Ebay seller with a lot of sales and a very high feedback rating is your best option, but it's no guarantee you won't still either get a lemon or get a board that the seller thinks is fine but truly doesn't have all that much life left in it. This is exactly why I try to tell people that IF you plan to use your platform beyond whatever time the hardware lasts, buy a second motherboard, because the motherboard is the one thing that will probably fail and can't easily or cheaply be replaced later on, so having a replacement, and getting it while prices are still reasonable, is a good idea.
At some point they become very hard to come buy and the prices go through the roof. Or, you take your chances on a used board.