Dude, I hate to break it to you, but staying with a "host family" while you're doing a language course is a huge scam and always has been, and the vast majority of the families do it for the money, not because they want to meet international students or w/e. It's very different than doing a genuine exchange programme (where the host families usually don't get paid), and it's not unheard of for families to have like 5 students staying with them because it's good money. It's the same in the US.

You can't compare it to what food and rent usually costs in the city - if you wanted to save money you could have tried to find a room yourself, but you didn't. And unfortunately switching might not make a big difference.