So, my widest angle lens is a 62mm.  I will likely use filters for lenses of 72mm, 62mm and 55mm.  I am now set on the "need" for a filter system, not knowing to which to put the cash.

I will check into the larger filter sizes but wonder if what works for the 72 will be large enough for the wider angle 62?  Then again, how many filters are stacked will make a difference, I am sure.  Likely, I will start with polarizer, grad ND and ND.  That should cover most of the sort of shots I do now.  

Anyway you look at it, the sum for all comes up to a fairly dear amount.  That is why versatility is so important...to be able to move from one lens to another without problems.   Tom.