Welcome to HomeVal, a FREE home evaluation site! This will give you a good starting point when comparing homes of different sizes and ages in the same general area.
Simply type in your target cost per square foot, then input the stats of the home you are considering purchasing. (Please use only digits in these fields!) Next, select the appropriate values for the dropdown menus (use "Don't care" if you are unsure of the answer). Finally, click "Get Score" to see how this home scores.
While that score alone is already a good indicator of the home's subjective value to you, it's best when used as a relative number for comparing two different homes.