We had property taxes go down (based on declining home value, of course). When renting, I never had my rent go down, even if the building values went down :)
You're right, though, on tax/ins. They tend to be a much smaller portion of the outgoing. Currently combined, we're at ~$3000/year for tax/ins. Even if that went up by 20%, it's an extra $50/month (wouldn't be happy about that, but it wouldn't break the bank). Rent of $2100 going up 20% is a much huger issue.
You're right, though, on tax/ins. They tend to be a much smaller portion of the outgoing. Currently combined, we're at ~$3000/year for tax/ins. Even if that went up by 20%, it's an extra $50/month (wouldn't be happy about that, but it wouldn't break the bank). Rent of $2100 going up 20% is a much huger issue.