You're probably going to have to be more specific. Like EOD or tick data (to mention two example extremes).
One exchange about $500/month all exchanges $1500/month. Your prices may vary (just mail them and ask).
Www.iqfeed.net is cheaper but may not deliver as many tickers at once unless you pay more. Www.polygon.io another choice.
Do you need full depth? Tradier will do around 1k streaming NBBO for free. Polygon with an Alpaca account will give you full market NBBO for free.
In my opinion TC 2000 can stream the entire NASDAQ, NYSE, AMEX. Don“t know if you need the data for your own application.. If not TC 2000 maybe the cheapest choice, 44 $ for realtime.