Facetious answer is the price should be zero, to match the price of other similar services.
More useful answer is to speak to some of your prospective customers, see how much value your service will add, and ask them how much they'd be willing to pay for it.
Anything else will be a guess.
A good start could be comparing with what are you going to compete:
For instance Country Reports charge differently based on the use of their reports, e.g.:
Perhaps now you should research how would you segment your market, which type of customers are you going to serve and which are their alternatives (other competitors).
Rule of thumb: if the customer perceives is getting more from you than from Country Reports reports you are going to be able to charge more than them.
Bear in mind that the exact price is not a guess, you should continue your research on other competitors, and try different segmentations according to the industry if you are targeting business companies see Gartner classification for instance.
Pricing is basically a factor of demand and supply. Hence you should project your demands at various prices, looks for competitor's price vs. their offerings. One important question you need to ask yourself, will you pay that much for whatever you are offering...
One important issue is worth of your products in the hand of the user. The profile of your customer also matters in pricing. For example, if you are pricing at a level, which reduces the comparative risk of your customer, you are likely to get more subscription. People will prefer to try your services more if they can afford the risk.