Stop and save your money. Flooded basement are a lot easier to fix than that. With every heavy rain comes worries about basement floods and leaks and so-called basement waterproofing contractors. These unscrupulous sneaks turn on the hard sell to get homeowners' valuable cash for treatments that neglect the real causes, all of which you can take care of on your own.
Bottom line, most flooded basements happen because of poor outside drainage conditions. Invest your time in cleaning and extending your downspouts, and re-grading soil to slope away from exterior walls.
Also pay attention when you're making additions and enhancements to your landscaping: plantings placed too close to the foundation will keep water close, too, and the same goes for decorative borders.
Take care of these, and you'll easily be able to resist pitches for expensive drainage systems that require tearing up your basement floor, and panic-causing claims that your walls are on the verge of a mold-covered collapse. It's all nonsense designed to scare you into opening your wallet. Flooded basement are just not that hard to fix.