These should be more than enough to get your domain in front of tons of potential buyers. If you did a good job picking an awesome domain, you should have no problem (eventually) selling it. You need to be very patient as it could take months or even more to land a decent deal. A lot of domainers sit on domains for years before actually selling them. This is why it’s best not to obsess over a domain and simply move on with buying and listing others (or going back to your day job if this is a side gig) once you've listed the initial one.
In theory, you could technically acquire a domain for $10,000 and be able to sell it for $100,000. You could also acquire a domain for $10 and be able to sell it for $100,000, $10,000… or $100, you get the picture. Because of this, it’s hard to recommend a perfect starting budget because your strategy, experience, and the pace at which you learn will hugely affect your buying and selling decisions.