We are both 67, strict budget travellers and our plans are to shop at MBK and J2JK . They both have excellent BTS access and we need a budget hotel ($30?) within a 5 to10 minute walk. The neighbourhood restos must have some "non tourist" food menus. Our diet is the key to staying healthy as is avoiding the mid day heat.
We have stayed near J2JK weekend market, but for example, the quality and cleanliness of the food courts at Big C left much to be desired. Everything else was convenient. Never stayed in the Sukumvit area. Our hotel room must have a King Bed or 2 twin beds, fridge and Wifi and a Thai or western breakfast would be nice to have.
Any personal experiences and recommendations can be messaged if you prefer.