Spikeman, tell your parents the following reasons why a good graphics card is needed:-
1) Improves the internet. Everything looks sharper, and so on (not true, but don't worry)
2) Microsoft word will load faster
3) The powerful graphics card will improve the computer's speed, cos it takes strain off the processor.
4) Will mean less upgrading is needed, because of number 3
5) Extra RAM, so everything loads faster.
6) Do you have a scanner? If yes, then larger images can be scanned in, less system "slowdown"
7) DON'T mention better gaming as your main reason.
'I reserve the right to contradict myself' - Richey Edwards, 1994.