Tied tubes? Was it a mistake?

I tied my tubes after having 3 girls. My BD and I are not together anymore. Ive been in this new relationship for 4 years. He has no kids and is the best father my kids have. I know it costs $6,000 just to untie them and this is an option for us but I want to know what everyone else has done. Maybe youve done nothing. I want to know. Maybe you have searched something to fix this and found something. I want to have kids with him, he would be a first time dad. What other options is out there?