Macro filters (actually they should be called lenses) & extension tubes both limit the magnification. Except for the pricey 2 element version filters, filters are pretty unsharp towards the edges... A true macro lens allows for varying magnification ratios simply by turning the focus ring. With tubes & filters, you have to add or subtract different ones to change the ratio.... That fact, plus the fact that doing that takes time, makes them less convenient. As for a wide angle lens, I'd agree with the Sigma 10-20 as I have one as well. Doesn't do macro & it's a DX format lens.
shagbat wrote:
For about the same money, you could buy an OPTEKA 10X
macro converter, or even a stack of cheap macro screw on filters, this would be your cheapest introduction to macro.
Auto extention tubes might be another option, but more costly. For wide, if your budget runs to it, consider Sigma's 10-20mm. I love mine!