Regarding expenses.. i honestly think neither one out weighs the other as if you BF you need to be having a good stable diet, taken vitamins, buying breast pads, nipple creams etc etc.
Honestly, its not that overly time consuming. You wash the bottles as you do your dishes and stick them in a steriliser. And you boil water as you do for a cup of tea.
I think that you've rather overestimated the cost of breastfeeding.
We all should have a good diet regardless of how our babies are fed and a good diet is actually cheaper than an unhealthy diet. Even if you have a dreadful diet you can still breastfeed. The same bottle of vitamins I was taking when I was pregnant is still in my fridge. I take one every few months if I remember. If you have a good diet you're just going to pee out most of the contents of the pills. IMO the breastfeeding part on those vitamins is a marketing ploy rather than accurate dietary advice. 1 tube of lanisoh lasted me for my entire BF relationship with each of my boys - after a week or 2 you don't need them.
Breast-pads aren't a big expense and re-usable ones are even cheaper.

For me even 1 extra thing in the washing up is too time consuming lol - I hate washing up.