Maternity clothes for working mom’s!!!!

I work in a professional setting and I have to dress accordingly, but every where I go to shop they only sell maternity leggings and jeans. When I look at specialty stores dress pants and dresses are $45-$65 per item (sometimes more!!!). Now, I have paid for maternity pants at $35 but I need more than just one pair or one dress at $55. I don’t make a lot of money to be spending on clothes I’m only going to wear a few months. I have invested in my wardrobe on items like cardigans and nice dresses that I have worn multiple times over the course of 3-5 years. It hurts me to spend this money when there are things I need for my baby! I have started to go to Goodwill type of stores to try and find clothes and I’m having a hard time finding maternity work clothes. What have you guys done?