I'm from SG; if you DIY it can cost as low as 30 bucks without a CO2 system. Or if you go the hi-tech CO2 route it'll cost 100++ as cheap CO2 systems tend to be less reliable.
There are shops that sell complete sets with or without plants/lifestock. Buying display pieces that are already planted will be significantly more expensive. For longer term upkeep you will still need to get fertilizer, and decide on a carbon source ( either CO2, seachem excel/metricide, or soil decomposition).
Well-kept planted tanks are a bit more troublesome compared to keeping fish, so you'd want to do a bit more research before deciding what to get. All the larger shops will have all the components you need, you can even order through online retailers that will deliver everything to your doorstep at a slight premium.
DIY tank under 50 bucks using garden soil substrate & ikea desklamp
In addition to the tank & substrate you will need:
Filter/pump (pump if you decide to be filterless)
Carbon source (CO2 or Excel or soil decomposition)
Fertilizer (NPK + Fe + Traces)
Plants & hardscape/rock/wood etc