The only difference between the formulas is ingredients but that doesn't make one better than another.
All have to adhere to pretty strict nutritional guidelines and the manufactures do change the ingredients from time to time but it will still have the same nutritional value.
So the cheap ones are no worse and the expensive ones are no better, they just gave a bigger marketing budget.
I'd just go with the one that's most readily available in your area. Nothing worse than having to travel far for formula with a hungry or sick baby or bad weather and I wouldn't be relying on deliveries for my baby's food.
Also, he aware that some babies can get gas from Perfect Prep so if you are using one and baby is unsettled, try making up the bottle without the Perfect Prep for a couple of days to see if things improve.
Tongue Tie can affect babies whoever they're fed so have a read of this on the symptoms too.
Baby will need ending more than a BF baby so try some different positions like the Tiger in the Tree.
Follow on isn't recommended at all, the NHS recommend staying with first stage till 12 months.
The only other difference I can think of is that you don't need to give them vitamins until their daily amount of formula goes below 20 Floz, unlike a BF baby who should have them some from birth.
Well the main difference will be buying, storing the milk, washing and sterilising but you know that already 