(MONEY Magazine) – It's simple enough to find a brokerage that will let you buy and sell stocks for a fee. But what if you also want a little advice? These days, a lot of brokers prefer to call themselves consultants or "wealth managers" and don't want to spend too much time with people who have less than $500,000 or even $1 million to invest. So we set out to discover what kind of advice the rest of us can get. (And what it costs.) It wasn't easy: Most brokerages offer a baffling array of service levels, and at the old full-service firms fees and commissions are often negotiable. To give you a starting point, here's a sampling of what four major firms are offering to what you might call investing's middle class--people with $100,000 or less to put to work.

-- MERRILL LYNCH With $20,000 in cash or securities, you can open a cash management account with this full-service giant. At this level a team of brokers will likely put together a fund portfolio for you. To maintain your account, you can choose to pay by fee or by commission. Will you get stock-picking advice? That's at the discretion of the brokers you've been assigned.

-- UBS For $50,000 in assets, full-service UBS offers the fee-based InsightOne account. The annual fee, charged quarterly, is negotiated with your broker. (The minimum is $1,250.) Services run the gamut: A broker can help you pick stocks or funds, develop an asset-allocation model or plan estate strategies. A minimum of $100,000 gets you into the Access program--essentially a portfolio run by an institutional money manager and supervised by your brokers. Fees for this top out at 2.8%.

-- CHARLES SCHWAB The once no-frills discounter is increasingly in the advice business too. The minimum to open an account is $10,000. For a quarterly fee of $1,000 or an asset-based fee as high as 0.75% (whichever is higher), you can sit down with a broker in Schwab's Private Client program. (You get some free trades too.) A cheaper way to get individual stock and fund selections is to ask for Schwab's Advised Investing options. You'll get one or two annual portfolio consultations by phone with an individual or a team of advisers. This costs $125 to $250 per quarter.

-- FIDELITY For smaller investors, this brokerage keeps things refreshingly simple. Just $2,500 opens an account, and you can even meet with a representative at one of 92 investor centers. You won't get stock recommendations, but a rep will help you select mutual funds based on a target asset-allocation mix. At $50,000 you can get a discretionary account--that is, a broker makes trades for you to ensure that you are sticking to your investment plan. But again, the rep will be putting you into funds, not stocks. The annual fee for this account is 1.1% of assets. --MEGAN JOHNSTON AND ELLEN MCGIRT