According to 3camels this is close to the lowest price since 2014 - the regular price is around $50.
From manufacturer's website[fluvalaquatics.com]: The most technologically advanced aquarium heater available today, Fluval E300 Advanced Electronic Heater, with VueTech technology, delivers peace of mind thanks to several excellent features.
Equipped with an intelligent digital microprocessor monitoring system, with dual temperature sensors, this 300-watt heater continuously monitors and displays aquarium water temperature, ensuring the safety and well-being of your aquarium inhabitants.
!!!Chance to make the deal even sweeter!!!
If you never used Chewy.com before, you can enjoy their extra 20% discount for autoship order. Autoship can be cancelled at any time.
$49.32 order will qualify for free shipping + if you set up an autoship of Seachem Safe e.g. every 16 weeks, it will give a discount of 20% off the whole order, so the total will be ~$40 + tax. You can add other stuff from there (they have more Seachem products available for the same or lower price as Amazon) and get 20% off the whole order up to $15 (so $75 order max).