Like said by Asuka, you definitly need a great macro, and that is more important than the number of megapixel (from 5mp its great, you're not doing billboard pics or posters so you won't use higher anyway ;-) )
From that price range, I would advise you to look the following cams to check the macro quality ;-)
* Nikon Coolpix L15: 8,29 MP, screen 7.1 cms (has an optical stabiliser)
and slightly more expensive but better IMO: 179