I remember paying a ton because I enabled mobile data in 2009 to check the score on a football game. My normal bill was ~$50/month for unlimited talk/text, and a few megs of data to check the score on one game doubled my bill that month.
It wasn’t until 2011/2012 until I had a plan w/ data, and even then it was kind of expensive and slow. I remember switching to Google Fi pretty early on because it was only $10/GB, which was a really good deal at the time.