It won't make any difference. Modern track spikes are allready that light the dfference in weight is negligible. If you really want to run lighter, try the following:
-shave your legs
-run without socks
-wear no underwear
-buy thin and very light shoelaces and make them as short as possible
-remove the insoles
-shave your head as well
-remove your lipstick
...
And save you a 100 dollar!!!