Chicken breast:
$9/kg (average)
21g protein per 100g - 210g/1kg
23g protein per $1
BN WPC:
$29/kg (when only buying 1kg)
78g protein per 100g - 780g/1kg
27g protein per $1 (or 39g per $1 when buying 5kg at once, as most seem to do)
Obviously there's more to it than how much you're paying for a gram of protein between powder and "real food" like your goals etc (wholefoods better for dieting as they're more filling, etc)....but seriously, before you* (*not directed at anyone specific) go harping on about "real food" being superior and/or cheaper....some simple mathematics might open your eyes. Given we're discussing protein sources (not fat, carbohydrates, or micronutrients), WPC represents the best value for money. End of discussion. You can keep your excessive volumes of meat; I'll keep my money and sip on my shake while you prepare and shovel down that rather filling steak (FWIW, I f**king LOVE steak and would never ditch eating meat just coz powder is cheaper).
My point here is exclusively aimed at the bullshit that keeps being repeated about meat being cheaper and supplements being a waste of money, which isn't accurate. Wholefoods are better for you (still arguable depending on the food itself), but by no means are they a cheaper source of protein for the average person who doesn't buy multiple kilograms of meat at once.
The same mathematical breakdown can be applied to the argument of WPC vs WPI. Per gram of protein, WPC is cheaper. So unless you have digestive issues forcing you to buy WPI, or you legitimately dislike the taste/texture of WPC, you're spending more than you need to.