You should avoid using Alpaca’s Polygon data feed because it will stop working on Friday. But to answer your question, even $1 would give you access to it. That’s actually why we’re losing the free Polygon data feed. People were leeching off of it without actually using Alpaca to trade:
It has become more and more apparent in recent months that some users have abused this system. Opening an Alpaca account not to actively trade, but to receive free access to polygon.io data. This is neither a win for Alpaca or polygon.io.