Hey,
I use a 5gal containter of generic round-up. Since round-up has lost there patten. Alot of hardware stores in my area sell 2-5gal jugs for $110 which just went up to $115. They will charge extra if u just buy 1 jug but will make it a little cheaper when u buy 2 to help them make more money.
BE Careful! Check with you AG Dept. There are many states you have to be certified and or licensed to spray commercially and some states apply pre-emergent and etc.

If it rains, the rain can even wash the chemicals into the plants & etc that is nearby.

Hope this info. helps!

Cjslawnservice