The lens correction software may be able to counter lens distortion and chromatic aberration distortion. Also perhaps it can counter poor contrast to some degree. But a good lens has more to offer:

• Sharper image. The lens correction cannot restore image detail lost due to an unsharp lens.
• Aperture. Good quality lenses typically have a larger aperture. You cannot recreate the narrow depth of field from these larger apertures. And in low-light, you can only compensate by raising the iso on the camera, leading to more noise (which may be removed by software, but produces a softer image)
• Quality of the bokeh. A good quality lens produces a more pleasing bokeh than a cheap lens.
• Faster focus.
• Non rotating front element, making it possible to work with petal shaped lens hoods and polarizing filters
• It is nice to have something in the hand that feels solidly build

So you cannot let good software be a replacement for a good lens. IMHO, you should get the best possible lens within your budget that suits your needs.