Consider how much value you're likely to get from any form of investment advice.
If you don't subscribe to anything, and do no research, but just purchase an S&P 500 index fund, you'll probably earn around 8% in the long run.
Now suppose you decide to pay for a service that provides investing advice (a publication or financial advisor). For this to make financial sense, you need to expect that following the advice will increase your earnings by more than the price. If the service costs 1% of the capital that you're investing, it needs to increase earnings by at least 1% (this is a bit of a simplification -- active investing can also reduce portfolio volatility, which is helpful in short terms).
But the situation isn't actually so bleak. Even if the increase in returns is not enough to offset the price of the advice, they compound over time. Eventually your portfolio may grow to a size where the cost of the service is well worth it. On the other hand, that will also happen with the index fund, so you might choose to wait until your investment grows to a size where it's worth getting more active.
However, there may also be non-financial considerations, as @BrenBarn mentions. Simply parking your money in a few mutual funds is boring. If you consider investing to be an interesting process, it will be more fun if you do it actively. In that case, you can consider subscribing to financial data similarly to a sports fan subscribing to Sports Illustrated. Even if it doesn't increase earnings to compensate for its price, you're enjoying the activity more.
Another factor is that as the size of your portfolio increases, more investment avenues open up for you (e.g. hedge funds). Many of these investments have eligibility requirements: minimum net worth and initial investment amounts. These types of investments are also more complicated, and you should seek out advice before considering them. The price of this advice is likely to correlate with the amount of your capital that you're investing.