Thats expensive.

It's often easier to find ammonium thio in solution.

60% is just about saturated.

One would mix it down for a working strength, but yes. 600 grams for a liter.

You can make your own Am thio with sodium thio and some Ammonium Chloride too.

If you need a source for Am thio, talk to the folks who make or sell fertilizer. It's who I get it from here.

55 US Gal is about $300.

Sounds like you might have reagent grade. Far to pure for what you need.