It depends on a lot of things:
- How many exchanges?
- How reliable do you want the feed to be?
- What does your typical customer use your feed for (satellite delivery of all symbols, or watch a few hundred?)
- Will you build your own ticker plant or buy someone elses?
- If the former, how many engineers will you have to deal with options switching to penny-multiples, for example?
- How much history will you maintain?
- How much tick history?
- How much will you pay to backfill data?
- Will you keep external data? (Commitment of Traders, Implied Volatility of options)
- How many people will you have to enter new futures and options contracts? (Expirations for options are entirely different per futures contract. Things like, "the last London banking business day on a Thursday followed by at least 3 week days.")
Feeds alone may cost $50k/month (I'm extrapolating from the known prices of CME, CBOT, and CBOEs feeds. Throw in NYBOT, NYMEX, LIFFE, Forex, etc., and it's getting pretty steep) Add tier 1 or 2 hosting, redundantly distributed across the country (or world, depending on your customer base), and add another $10k/mo+.
There are then exchange fees which you are required to pass onto your customers. DTN pointed out recently that a feed company has a different set of rules than a broker for distributing data. For example, IB can hand out CBOT electronic contract data in realtime for free. DTN is required to charge the "full" CBOT fee of $55/mo.
Add to all of that the fact most customers want a complete (and free) technical analysis package as part of their data feed.
If you were putting together a business plan, you'd have to do something extremely different from everyone else, and people would have to be willing to pay a premium for it. This couldn't be a "low cost" competitive service.
I'm no expert, but I did look into the costs for getting a full CBOE feed at one point. So, take my comments as a semi-informed party.
