If you need both good measurements that should by ample margin be audible transparent, as well as enough power for virtually any headphone save those that need a special amplifier (electrostats like STAX's), you'll find it hard to go under $200.
This device is actually a gem for the price, and most popular recommendations will go higher in price and give you less. I have been there and done the digging, you're welcome to repeat the process.
At some point, new devices or new prices will change this. But, as far as I am aware, this is how it is right now.