Well if you didn’t get free breakfast at your hostel then grab some street food or head over to the nearest 7eleven. If you ask anybody that’s been to Thailand before they’ll tell you that 7eleven is the “plug” for some ham and cheese toasted sandwiches. They cost ฿25 ($0.75) and they’re in the cooler but when you bring it to the register they’ll ask if you want it heated up. YES, you do. They put it on a little toaster and it’s SOOO good. I usually start my morning with a coffee and ham sandwich from the 7eleven.
Eat the street food. Pad Thai is everywhere in Bangkok and it only cost about ฿50 ($1.50)-and that’s usually with chicken. You can also find a lot of other options like garlic chicken and rice for about the same price.
You can get a large Chang- Thailands local beer (and one of my favorites) for ฿80 ($2.50). If you plan on drinking a lot then I suggest going to 7eleven and buying a bottle of liquor there. They sell buckets (a literal bucket of liquor usually mixed with red bull and a coke or sprite) everywhere but a lot of places switch out brand name liquors for really cheap/watered down liquor.