I've definitely been on the other side of that. I refused to buy a nice rain jacket and got one off the bargin rack for 30 bucks or something. It was very light but very much not water proof. After 1 trip of being soaked through while being rained on for 2 hours I stepped up and bought a nice as rain jacket. Luckily my layers were good material and still held the heat. It's not fun being soaked when it's 50 degrees. I'll admit I'm a bit of a salley though.
Given, it's not a $600 rain jacket. I was pretty pissed at wasting the first 30 bucks. I think my new rain jacket was $110 or $120. Well worth the investment.