Depends on your budget.

If you don't require hot or cold water, can get undersink type like Aquaphor with a faucet at the sink.

There are minimalist style undersink purifier with hot water (with tank) like Intrix and hot + cold water like Wells; this options are costly.

For table top minimalist design can get LG, as this model have flexible nozzle arrangement; allowing you to install flush against the wall. For the water inlet, outlet and plug, you can hide it all if you drill a grommet. Making a neat installation.

U dont just look at the annual maintenance price. You have to look at the price per water filtered when u need to replace. Unless you are talking about staying in the house with 1-2pax, which is fine because probably the usage is low. Annual fee between RM500-600 is the mainstream majority brand/company average pricing.