I aim to hit 300 grams protein everyday and shakes play a bit part in this when I dont have the time to prepare enough eggs and meat.
Some days I will two monster whey shakes each with 80 grams protein (total 160), and maybe one more shake of 40 grams protein (total 200); and then the remaining 100 from eggs, chicken, lean beef, fish etc..
Of course, it is best to get as much protein as possible from solid food. But if you are always falling way short of the 1.5 grams per lb (or 2 grams per lean lb), then make up the difference with shakes.
I have made good gains using whey as my major source of protein. It's far far cheaper than meat (about 80% cheaper because I live in Korea and can get it in bulk for dirt cheap).
But try and fill up on solid food first and bridge the gap with shakes (dont worry about the 3 scoops per day thing, whey wont hurt you).
Also try and prepare meals in bulk. Example I will cook 1kg chicken breasts in a stew with sweet potato and vegetables and that makes 5 meals with 50 grams protein each. This is one weeks lunch at work. I will also cook a number of steaks at once and freeze.. So my freezer is always full of ready to eat high protein sources. And my bag always has at least two monster whey shakes every morning for while Im at work (so at work I get 50 grams from my chicken and veggies, 80 grams from whey shake 1, and 80 grams from whey shake 2 = 210 )
Not so difficult
But I am following a 16/8 intermittent fasting style of eating, so I only get 8 hours to get in my protein and calories, and I still hit the 300 range daily.
Just do it!!