Does anyone have a model of the value of tax deferment? Is it worth putting pre-tax dollars into an employer sponsored plan
that sucks in the hope of being able to roll over that money into a self directed plan in the future?

I ask because my wife has been offered a SIMPLE IRA with 6% loads and 1.5% annual charges.

I would tend to say go with the plan until you added the costs.

I assume no company contribution.

You have to give the employer credit for at least setting up a plan and giving you a choice. It is a start and may get better.

First she should go with a regular or ROTH IRA.

The difference between the tax deferred investment and the taxable is:

Upfront income tax saving for the SIMPLE IRA (and a regular IRA)

SIMPLE and regular IRA is taxed at regular income tax rate when money is taken out.

Money is tied up for years (not so bad if this is for retirement)

In the regular taxable investment you can avoid taxes by investing in non dividend paying stocks.

The gain in the taxable account will be at the capital gain rate and less than the tax on the regular IRA money.

You can run the numbers on a spread sheet but I think you will find a ROTH IRA best followed by a taxable stock investment.