It depends on quality and material you want to use.
Buy those ready made wardrobe, furniture, kitchen sink etc are cheaper than custom made one.

30K is doable for basic.

Custom made is costly nowadays, due to labour cost primary, and quality sometimes worst than pre-made, my experience.
Good only is it fit exactly to your room dimension.

How about for 650sqft (2 bedrooms + 1 bathroom)? RM30K enough for renovation (including plaster ceiling living+kitchen+bedroom, kitchen cabinet, wardrobe, furniture & electric appliances)?

Is plaster ceiling a must?
- My new bare unit is w/o plaster ceiling .. because its NEW

Kitchen Cabinet?
- Just get the basic one first such as counter top and appliances : fridge, stove and/or hood, microwave / oven toaster

Wardrobe
- Can get the cheaper set if budget is a concerned or custom made which is what I did for certain bedroom items

Furniture
- Can get from Ikea is most item is suitable for small living space or just get it cheap from set items outside

Electric appliances
- Depending on brand, you can adjust to your liking but average per items is not cheap. Although some item can be purchased later on such as washing machine