I decided to try to eat everyday 5 portions of fruit and vegetable. First of all, it's not cheap at all ! Here in America, fruits and vegetables can be expensive, so when I go grocery shopping I focus on fruits and vegetables that aren't too expensive like: cucumber, grapes, apple, carrots. Of course I wish my 5 portions would be all like strawberries, mango, pineapple... but those can be a bit pricy sometimes like $6 for strawberries :(
Also if you are going to start doing this you need to try to plan ahead and determine how much of what is actually a portion.
An on-going research is trying to show that skin tones change after 6 weeks of eating 5 portions a day.
To help you determine what is a portion this pdf will be very helpfull: