What steps would I take to hire a developer to build a bot?

I apologize that this isn't a strictly programming related question, but I wasn't sure how to narrow my search for something like this.

I'm interested in hiring a web developer to build a bot for a trading card website. When an employee needs to buy/sell a card to a customer, the bot would pull the price from a trading card site.

-Where would I start for hiring someone reliable and relatively cheap to create something like this? -Again, I'm sorry if this a bad question for StackOverflow. Where would be a more appropriate forum for something like this be?