I bought the 6 month magoosh GRE prep and found it extremely helpful. I'm not a strong standardized test taker and it really helped me. I studied for about 3 months off and on and the final month I studied quite a bit. I definitely could have studied more, but even with that little amount of prep I was able to score 152 V, 153 Q, and 4.0 W. Not the most amazing score but definitely fine when applying to grad school. The questions from magoosh are super similar to those on the GRE if not a little bit harder. It also gives you projected scores, and my ultimate GRE scores were exactly what magoosh predicted. If you are able to afford it I would 100% recommend magoosh. It's almost fool proof and does all the work of creating a study plan and coming up with study questions for you. Also the complete breakdown of each question in written as well as video form is super helpful.