Hi Dennis,
Depending on how you define "nice clear closeups," you may have difficulty buying a "nice new camera," with your budget. Typically, for "Macro" photography, you need a DSLR and a Macro lens. A good Macro lens, new, will eat up most, if not all of your budget.
If I were you, I'd look for a used DSLR with a kit lens. For instance:
Canon RebelXt or Canon T1i/T2i with the 18-55mm kit lens OR the 18-200mm lens.
Canon 40D with a kit lens.
Nikon D40 or D70 with kit lens.
Then, I'd also start looking for a used Macro lens, such as the Canon 100mm Macro. Don't get the newer version, with IS (Image stabilization) as you don't need it. Find the older version of the Canon 100mm Macro. It's an amazing lens!
Even used, you'll have a difficult time coming in, in your budget. A decent RebelXti with kit lens, will still run you about $350.00ish. A quality used Canon 100mm Macro is going to run $400.00, unless you're very lucky.
If you're able to increase your budget, and want something that will also shoot HD Video, I'd consider the Canon T2i or Canon 7D, though the Canon 7D shoots your budget all to heck...lol.
I started out with a Canon RebelXt, several years ago, that I purchased used. About a year later, I purchased a Canon 100mm Macro. Now, I've upgraded to the Canon 7D, with the 18-200mm IS lens. I also have the Nifty Fifty 50mm 2.8 and the 100mm Macro. I'd say about 90% of my tank photography AND most of my portraiture photography is shot, using the 100mm.
