The concept behind Cokin filters is brilliant: instead of investing in screw -on filters for all of your different sized lenses, you can invest in a filter holder system that adapts itself to different lens sizes.
I discovered, too, that it's often possible to acquire nice Cokin sets on eBay. Although the Cokin filters on eBay are predominantly the larger professional "P" series, one can occasionally get the amateur "A" series on the cheap. I saw a couple of such set go for the starting bid when I jumped into the fray. I, too, got my set on just the first opening bid.
I got the adapter/holder for my 58mm lens size, plus a very nice assortment of filters:
- Close-up +1
- Close-up +2
- Close-up +3
- Polarizing
- Gradual G2 (two of them for stacking)
- Gradual Y1
- Gradual T2
- Gradual M1
- Parallel B
- Warm (81 B)
- Star 8
- Fog 2
- Blue (80 A)