For me...I've lifted since I was 14...
Unless you are a Professional Bodybuilder, retired, or Trainer for a living....Its hard to get 6 good meals in...even if you can affordit. If you are tight with money...forget about it.
I've been buying 5-10 lbs of Optinum nutrition 100% whey protien for years. I have 3-4 protein meals a day from Protien shakes. Also you should have a meal every 3-4 hours, and at work or school thats tuff, so I carry 3 shaker bottles around with two scoops of powder in it....then when its time for a meal....I go to a water foutain and add the cold water....Piece of cake. The other 2 or 3 are Tuna Fish, or Talapia. It saves time and money....cause in fast pace modern america....time is money.
Second...next easiest, cheap protien source is buying Cans of Tuna at BJ's or Sams club, or costco....or big bag of Boneless Tilapia Fillets that come in 4 oz individualy packaged in the big bag.
There you have....Buy Bulk Protein powder, Bulk Canned Tuna, Bulk Talapia Fillets.