Organisation and help is the key.

I have four boys and although they dont all play sport anymore there is many wknds where Aunty and Nanny were called in to help out as we had three different places to be at different times and Dad was working.
Yes you do get a discount for the more you have playing and there is nothing wrong with 2nd hand uniforms! Our club even has boot sales where you can pick up a perfectly good pair of boots for 5 bucks.

If you already are feeding five then seriously another mouth is another potato in the pot.
My older two eat for Africa and I just make sure I am organised and meal plan but also I use cheaper meats, (mince and sausages here no steak for us ) and loads of veges.
We use a loaf of bread a day easily but with careful planning and bulk buying my grocery bill isnt too horrendous.

We have our princess now too so I do find I am time poor at the moment and spreading myself a bit thin but as she is still only little I know it wont last.

Good luck I think you have the right attitude, dont sweat the small stuff and its all small stuff!