It's $170 from the official store (if you can buy it new, but third-party sellers are pushing them for two or three times the price). For some, this is nothing. For others, this is a lot.
As to whether it's worth the money, it depends.
For the money, it's hard to buy anything else that can do what the Flipper Zero can do. If you want something to experiment with NFC and RFID and sub-GHz wireless networks, it's a nice all-in-one tool. The GPIO outputs are also cool if you're into playing with hardware.
It also gives you the ability to run BadUSB attacks on devices.
But where I see the main power of Flipper Zero is less the hacking destination, but more the journey.
The Flipper Zero is a brilliant learning tool, and you will be learning all along the way.
What can you learn? How GitHub works, how to download and install firmware, how to flash hardware, what all the different networking and wireless protocols are and how they work, and how to work with GPIO -- for starters.