The caveat of having a retail margin account (distinct from a professional margin account) is that there is a limited amount of same-day trades you can make if you have less than $25,000 in the account. This is called the Pattern Day Trader (PDT) rule. You don't need $25k to day trade, you will just wish you had it, as it is easy to get your account frozen or downgraded to a cash account.
The way around THAT is to have multiple margin accounts at different brokerages. This will greatly increase the number of same day trades you can make.
Many brokers that offer a "solution" to PDT to people that don't have 25k to invest, are offering professional trading accounts, which have additional fees for data, which is free for retail trading accounts.