In terms of costs, 16 percent of small-business owners think plan costs are too high. A quarter of small-business owners — 27 percent — say they would reconsider offering a 401(k) plan if the overall costs were lower.

There is a lot of good news to share here. There are now 401(k) providers that offer pricing to fit almost any size company. Beyond a one-time setup, businesses typically will pay an ongoing administration or record-keeping cost, and other expenses are typically paid as part of participant investment expenses. For a 10-participant company, administration costs can be less than $1,000 per year, and the government offers a tax credit of up to $500 for the first three years of the plan to help offset plan costs. Self-employed business owners can expect much lower costs, although the credit won't apply.

One-third of owners said offering a 401(k) has afforded them both personal and professional tax breaks.

Many small business owners also believe five percent is a fair amount to pay for 401(k) fees, which can include investment expenses and administrative/service fees. The most important cost to manage is the investment expenses charged to participants, such as fund expense ratios and investment management services. Five percent is way too high. Every dollar paid in investment expenses is one less dollar invested in the markets. Keeping investment expenses under one percent is a good benchmark, and one you can achieve. With some online research, and asking a few questions around fund expenses and other costs paid by participants, you can quickly find some good options.