Are you able to recommend any reputable brokers that offer IPv4 addresses for a price suitable for individuals or small businesses? I only need a few addresses ideally.

Be aware that there are caveats in this approach. First, a /24 or larger range is compulsory for multi-provider BGP, which is, itself, compulsory for dynamic advertisement in the way you want. Second, broker ranges are only suitable for your use case if they are allocations rather than reassignments. Third, even when a broker has reassignable ranges, they need to then use detailed reassignment rather than simple reassignment for your new block. Otherwise, you will be unable to announce prefixes to providers requiring proof of ownership. Please refer to https://www.arin.net/resources/request/reassignments.html for detailed information on the SWIP process.

In every recent case I've seen (over the last six years), no broker has had ranges larger than /24 for reassignment. Of course, you can do with just a /24, but the justification process has also grown somewhat more stringent, as a pure traffic engineering justification ("We need BGP; here is why.") is no longer enough, in my experience.

No, sorry. I got my block for free during the early years of the commercial internet. You need a /24 (256 IP block) for it to be globally routable.

If you want to "own" a few addresses to play with, it is not technically possible. If you want a small block, you should just get a VPS that supports multiple IPs and tunnel them back to your location.

Can I use this with my own isp? Bring your own ip?

Or with azure?

If you have a "business" account with your ISP, possibly. For residential, it is almost certainly "no."

Last I checked, Azure didn't let you do external BGP announcements but I may be wrong...

Thank you for saying "external bgp announcements". I can go research now.