citizens supplies, or country supplies, effect country welfare. your pop will compensate you for the cost, mostly. so extra quality, will boost production, with a minimum cost.
for nearly all suuplies, set you "order strategies," to max 300Q. 5 things you should keep minimum, military supplies, military services, medical eq, medical materials, and Pharmaceutical Products. these have a secondary effect of increasing monthly military and health costs.
for higher than 300Q in your country supplies, you'll need to manually buy supplies. best way to do that, is maybe 2-3 times a week, look through the list of "Products in stock; buy and sell" look for those things that have a monthly use, and are green. when you look to buy it, gauge for your self, for me, usually, if it is near or below base price, i'll buy, if its above, i'm not getting a deal. buy doing this, you can build a stock pile of stuff, cheaply
also, long term, keep your corp and gov salaries even, what your pop and gov take out of supplies, they'll pay back about evenly. if you manually stock pile cheap products, when the price goes up, you'll end up making a profit off your own country supplies
and welcome back