Many, many data brokers don't "sell" user data the way you seem to imply. If you collected user data, you're in one or more of three categories:

1. You have a business model based on user data, like advertising, so your goal is to collect as much data, of as high quality as possible, to make your business more effective;
2. You have a completely different core business model but it enables you to collect data and you might as well monetize it;
3. You're a broker, an intermediary who's acquiring data from (2) and selling it to (1).

Brokers may be able to sell you data about you, but they typically don't care much about making sure it's you. It's not their core business, and they may have partial data that is about you, but they're not able to tell it's about you. A lot of data just doesn't have a neat name/address/phone number. Maybe it has your IP address, and companies in (1) will make that connection immediately, but brokers have little reason to care.

Data producers (2) maaayyyybe could, but they really won't want because (a) you're too small and they only negotiate data in bulk (b) they'd rather not tell the public what they collect exactly.

Data consumers (1) have zero reason to sell the data. They're in the business of augmenting that data and classifying it to know what's junk and what's reliable. If their competitors can get their hands on this precious secret sauce, they'll eat them alive. So they keep this data jealously.

There is vertical integration, especially 1+3 - that's what e.g. Google is all about, use a data-generating vertical (search, web analytics, email) to inform their data-using vertical (ads). Those are simultaneously the data hoarders with probably the most data about you, and the ones least likely to want to share that data with you. It costs them an entire free service to collect the data, and they're the only company in the world with it, there's very little reason for them to give up that advantage.

So yeah, it's unlikely you'll get anything of value. You're not relevant enough in their economics, sorry.