A RSTB and/or bigger rear sway bar definitely will help you with handling and not sacrifice the ride. The bigger rear sway bar may require some sub frame modification, but it will all easily fit into your budget.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
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