Before you invest, make sure you seek tax advice regarding which plan is the best option for you. With a Roth IRA, there are AGI limitations based on how you file your taxes as a married individual. Also, one of you has to be working and earning at least the amount being contributed. The Roth IRA has its perks. Since you are contributing after-tax dollars, at retirement it’s possible to withdraw funds tax free as long as the requirements have been met. Contributing on a monthly basis is a great way to build your savings, CDs are not the best investment vehicle right now as their rates are incredibly low. Try a brokerage or annuity firm.

You and your wife, if both working, should look into Qualified Plans offered by your employer (i.e. 401k, 403b, etc.). This type of retirement plan is a better option as your deferrals can amount to much more than the limited contribution amounts on an IRA as well as the perk of a match provided by the employer.

A better option is to invest in precious metals.
When you withdraw money from your IRA, you will have to pay taxes. If you invest in precious metals, you won’t have to pay taxes when you exchange them for money.

That does sound like a plan … especially if you do it under the current ROTH IRA plan. Use a good mutual fund company.
Check out the funds in Morningstar.com. Many of them will wave IRA fees if you do as you said here.

Also check out if your employer has a 401K that matches your contribution or at least a good part of it. Just don’t let it all be in one stock if you can avoid it.

If you want to earn a 33% return on your investment let me know.

Assuming you are relatively young so retirement is quite a ways off, your plan sounds good. Investing in a growth mutual fund or two through one of the large mutual fund companies would be good. If you just put it in CD’s or something, your purchasing power will decline over the years with inflation.