Step up ring: extremely low cost options seems OK
I needed a 52-77mm step up filter ring and was hesitant to pay the $10 to $20 one would pay in a local camera shop for one of these (notwithstanding the great people and service one gets from local shops).
I ended up ordering one for exactly $1.43 from ebay from one of those discount stores (in this instance in Hong Kong). Remarkably that price included processing, taxes, and shipping from half way around the planet to Canada.
It arrived yesterday. Looks great. Works well. Seems like a good way to go. I have another one of different size on order.