And thus far in 2012, the costs for owning ETFs have been falling. Fund providers from the Select Sector SPDRs to Vanguard and others have been slashing fees.

In early March, for example, Vanguard announced expense ratio reductions that included bringing the Vanguard FTSE All World ex-US ETF (VEU) from 0.22% to 0.18 %, and the Vanguard High Dividend Yield ETF (VYM) from 0.18% to 0.13%, among many other changes.

The Market Vectors RVE-Hard Assets Producers ETF (HAP), which is sponsored by Van Eck Global, recently reduced its annual expense ratio from 0.59% to 0.49%.

According to ETFguide’s first quarter data, here are the expense ratio medians for key ETP categories:

Large Cap Stocks: 0.20%

Mid Cap Stocks: 0.25%

Small Cap Stocks: 0.25%

Global & Intl Stocks: 0.53%

Emerging Mkt Stocks: 0.62%

Bonds: 0.20%

Commodities: 0.75%

Currencies: 0.45%

U.S. Industry Sectors: 0.48%