Pro tip: my $22 rice cooker paid for itself in about 6 weeks

I used to buy those little microwave rice cups for lunch every day, the ones that run about $2.50 each at the grocery store near my place in Tulsa. That was around $50 a month just on rice, which sounds dumb when I type it out but it added up fast. Back in March I grabbed a basic $22 rice cooker off the shelf at Target, nothing fancy, just a pot with one lever and a little light. I make a big batch on Sunday, portion it into five containers, and that's my lunch base for the whole week. A 5 pound bag of rice is like $6 and lasts me almost a month, plus I can toss in frozen veggies and a couple eggs while it cooks. My grocery bill went from around $310 a month to about $240, and I'm not even eating worse. Now I'm wondering if I should get a cheap slow cooker too, or if that's just me buying more stuff I don't need. Has anyone here done the math on those and actually saved money?