You certainly are correct. This payment wouldn't be acheivable with taxes and insurance at all, and it would be low regardless. The best way to get on track and truly know what you will pay is to contact a good mortgage professional. They can give you information based on your scenario. Your payment will differ based on the amount of your downpayment and your interest rate, which is dependant on your credit score.
Insurance is calculated in the same manner. One last consideration that adds to your monthly payment is the MIP (Mortgage Insurance Premium) that also accompanies a loan where you are putting less than 20% down.
A more realistic monthly payment would then be closer to the following:
These are not real numbers and only used for demonstration purposes.
Assuming a loan of 30 years with approximately 3.5% down at 6%, you would have payment of about $1230 per month. You can also use a more realistic calculator by visiting http://www.trulia.com/mortgage/calculator/payment/property/1
I hope this helps answer your question.