Interested in development sector but unsure about Ph.D
I would consider the following:

1) Do the jobs you want require a PhD? You may be able to have a satisfying career and a choice of many interesting and well-paid jobs (you define both of those terms for yourself) with a M.Sc. and on-the-ground experience.

2) Are you likely to succeed in a PhD? There is little point to pursuing a PhD if you fail out of the program. So, you need to assess your preparation and whether you are likely to be able to complete the PhD. If you are not sure, talk to some of your mentors who have PhDs.

3) Are you competitive for fully-funded PhD positions at respected universities? To make the time, effort, and opportunity costs involved in pursuing a PhD worthwhile, you should pursue programs that are fully-funded and that maximize the value of your degree post-gradation. These types of programs are more competitive, so you should assess (with mentor's help, if needed) your academic record and other factors to determine if you are a good candidate for such programs.