There are many strawberry farms in Cameron Highlands where you can pick your own strawberries, you won't have trouble finding one. Earlier this year, we went to the one inside the Lavender Garden. There was no entrance fee to the strawberry farm, but we had to pick a minimum of 100g (if I remember correctly). They gave us a small basket and a pair of scissors. Only two persons were allowed to enter with every one basket. So that means if you're a group of 3 or 4, then you'll have to take two baskets and pick a minimum of 200g of strawberries.
That day, we were the only two people at the farm, so we could really take our time choosing the reddest and juiciest-looking fruits. It was a fun activity. I doubt I could say the same had there been many other visitors around.
We picked about 12, got it weighed, and were charged RM11.80. If you buy it elsewhere, the same amount would only cost you half the price, or even less. The only advantage of picking your own is of course you can ensure that all of them are fresh, because sometimes if you buy prepacked strawberries, you may find a few overripe or moldy ones.
And, I don't know if you're actually allowed to do this--I didn't ask--but while half of the strawberries that you pick can go into the basket, the other half can be stuffed into your mouths, provided that you don't mind eating unwashed strawberries. It's not like there were any CCTVs around (we checked). I suppose the farm owners had already anticipated this, so they had included it in the price.