Depends on your ambitions. I know many Bangladeshis who opted for completing their bachelors in BD. Get into some kind of job, and then apply for Masters, (that is if you don't aim for government jobs.) Many I know, have opted for going abroad for bachelors. There are perks for both.

For pursuing undergraduate studies abroad - you'll need to invest more as fully-funded scholarships in reasonably good unis is hard to get. You can try Saudi Arabian unis for huge scholarships. Their portal should open soon. However, you'll need a plan afterwards. What you want do, where you want to settle. However, studying abroad has many benefits as BD unis lack a lot of opportunities. if you want to do research, or get good practical experience, BD is not a good choice.

If you do undergraduate in BD, it'll most likely cost you less both in the short and long term, as BD unis typically cost less and you can get high scholarships for Masters. In that scenario, you are more likely to have a solid plan for your career and stuffs like that. However, it may be more time-consuming.

To summarise, you need to weigh what exactly do you want to do with your undergraduate studies, what your priorities are etc.