Wow Plano. Reading these posts, I can see your point. Being in the industry, I can't bring myself to assign blame to the agents (mortgage or real estate), however, because I'm a big believer that every person needs to take responsibility for their own well-being... no one is going to look out for number one better than number one. So, get yourself educated on your options and find an option that works for you... or better yet, create an option that works for you.
In starting the home buying process I advise my clients to talk with a lender and get pre-qualified... and then get real. Just because the bank (or their software) shows that you can afford a loan doesn't mean that you actually can. The percentages that you see below are based on a persons gross income, which is often far different than a persons net income. And, lenders don't take into account a persons future financial goals (i.e. 401k savings, kid's college, Murphy's law, marriage, divorce, children, etc). You, as the person signing the contract for purchase need to lay out your plans and really determine (and sometimes discover) whether you can afford the house you want or not.
You don't have to be good at math either. Write down your net income on one side of the paper for a standard payment cycle (often a monthly cycle). Then write down your expenses on the other side. If you're like most people the expenses side is going to much longer (which is why I encourage my friends, family, and clients not to be normal)... but make sure that it is all inclusive (i.e. groceries, lights, cable, electricity, credit payments, car, savings, investments, vacations, vehicle repairs/registration, etc.). Also, compare what's written to what you're actually experiencing. If your paper shows a huge surplus at the end of the month and your bank account is showing the opposite, then the list isn't accurate. If you're not truthful with this exercise, you're only hurting yourself.
There are mortgage payment calculators all over the web and including my website. You can use one to determine what a mortgage payment is for a total purchase price... and you can find ones that calculate a total loan price based on a monthly payment as well. But that estimate should come from your determination of what's left in your budget... not what the bank "thinks" you can afford. You can also set a payment goal and find areas in your budget to cut costs to make it affordable... but perhaps more importantly, sustainable.
Something to consider is that the national household average annual income for a neutral family is somewhere between $40k - $45k with very little savings. I would encourage you to strive for better than normal. Normal in the "golden" years is living on social security with underfunded healthcare and the lack of funds to pay for family visits. I so don't want to be normal and I wouldn't wish it on anyone... Don't overextend yourself and get stuck in the rat race (yes, I read Kiyosaki).
Oh, and the responders were so "helpful" because you have a key phrase in your question... "wanting to make a home purchase." Be careful of free advice and make sure that you find a professional with the heart of a teacher to help you find your home.
Best of luck.