Pros & cons of breast vs bottle (with breast milk)

What are some pros and cons of breastfeeding from the breast and giving breast milk in a bottle? I'm kinda thinking of exclusively pumping and doing bottle. my LO is 4wks old. takes both breast and bottle very well. he will take cold breast milk just fine so warming it up isn't really an issue if I'm out, though I do have a thermos to warm up if i want. I also have a bottle warmer at home. *Edited to add* my insurance covers storage bags and bottles so I don't have to spend extra money. I'm also a SAHM, wanting to start online classes.