Waiter, There’s a Bug in my Frappuccino

//Privileged folks, always blind to their privilege.//
You're telling me you're not a priveleged folk yourself?  And you're speaking on behalf of all the non-priveleged folk you know SO much about?
 
//Do you think a family of five with the median household income of ~$50,000 pre-tax can afford to eat a vegan diet?//
How em, unskeptical of you.  The key to being skeptic is to first investigate all sides with rigor before coming to a conclusion, which you did not do.  You seem to have this idea that if you're a vegan, you have to buy super expensive vegan products and shop only organic.  And that's the part that makes you unskeptical.  All a vegan diet means is that you don't buy animal products.  You can still shop at Wal-Mart and Aldi and be vegan.
For instance
– Dried Beans, Potatoes, Sweet Potatoes, Canned Vegetables, Rice, Cornmeal, Peas, Corn, etc. <– These are somehow "expensive" items?  Not hardly, these are things that these "non-priveleged" people who eat meat buy.   So yes, it's quite possible on small budget. 
However, the monetary concern is not really the issue here, what makes it hard to be vegan are the following things
– It takes work to get a well-rounded diet, so you have to make sure you eat a correct balance of things.  You can do it cheaply, but it takes some knowledge and some cooking skill to do.  Children are fickle, so in the US at least, it may be hard to get them to accept eating a well rounded diet.  However, in India, vegetarianism is common, and families that earn less in their lives than a westerner earns in a year (you for instance) manage to do so for families much larger than 5.  However, the culture makes it much easier there to do so.  People know how to cook healthy and complex vegetable dishes (i.e. non-meat main courses) are the norm rather than the exception, so they manage it quite well despite living in mud shacks.  In America, it's not in our culture at all to make vegetable dishes as our staples, so a lot of people would simply not know how to cook a well rounded vegetarian or vegan diet.  This is more a disadvantage here than in India.
 
Basically the privelege lies not so much in the cost of food but in education.  If someone with a large family decides for moral reason to feed their family a vegan or vegetarian diet then they can do so just as affordably if they have access to a proper grocery store (like wal-mart) and don't live in a food desert.  So who are vegan more likely to be priveleged?  Yes, but saying vegan/vegatarian==priveleged (especially if you're implying that it's because it's too expensive) is bullshit.
– You definitely have to take your children's health into account, you may have to break the vegan/vegetarian diet in some cases.
//Really? Do they have the time to deal with hunting for vegan deals that they can actually afford? Maybe India is set up to feed people a varied vegan diet, but in America poor people are stuck with poor people food the vast majority of the time.//
What's poor people food, can you clarify?  I wonder if anyone who really grew up in poverty would resent that comment or not?
 
Vegan deals?  What, like pre-packaged dinners?  Vegans means = doesn't eat meat.  Last I checked common vegetables are cheap and people who eat meat also buy them.  If you know how to cook main courses out of vegetables, your budget is similar to any meat eater.
 
If they live in a food desert, yes of course, it's very hard to be healthy at all, much less vegetarian.  However, if someone lives live near a well stocked grocery store (say K-Mart) and conciously decide to be vegan or vegetarian, it's not more expensive or difficult for them if they know how to cook.  You can easily make a vegan or vegetarian diet out of what you get at a common grocery store.  They would need to decide this first however.  I don't expect anybody to just go vegan or vegetarian because I say so, I'd prefer they make their own decision about that.
 
Anywho my core point is that making the claim that "If you're a vegan or vegetarian, you're necessarily priveleged" is bullshit and definitely an unskeptical thing to say.  I think it's funny how people who count themselves as skeptic resort to pseudoscientific arguments like "single celled eukaryotes are animals", "bugs aren't animals", "plants feel pain", etc in an effort to find a reason why veganism/vegetarianism is somehow bad.  If you're going to make an argument, do your research like a good skeptic and make an honest fucking argument, not some pseudo-scientific one that validates your emotions.