Affordable integrated pure class A?

$166 for a class A amp?

Sugden.

You could build a couple of these and pair them with a small preamp:

https://diyaudiostore.com/products/amp-camp-amp-kit?variant=7072933085218

Otherwise, consider the Sony TA-A1ES. It's more of a quasi-class A, but still gives the class A sound - very smooth. These can be found in mint condition for $1500. Hard to do better for the price. However, it does suck a lot of juice from the wall as do most class A amps. 

The Belles is class AB.
IME, a good class AB amp can rival class A. Though I'd rather have a class AB tube amp than a class A solid state amp. You must also consider the long term cost of class A amplification. My electric bill was about 30% higher when running that Sony integrated (3 hours/night), despite its greater efficiency than typical class A. 

What speakers are you pairing it with?

Sony TA-A1ES. The amp sounds really smooth and musical.

https://www.google.com/url?sa=i&source=web&cd=&ved=2ahUKEwj_26udx5HfAhVj6IMKHfaEAmMQzPwB...