A miniature painting kit sold as a boxed product and the kit a painter actually needs are different lists, and the difference is worth knowing before spending. The genuine requirements are short: a way to prime, a small set of paints that work together, two brushes, something to hold water, something to hold the model, and something to protect the result.
The list that actually matters
Primer, a starter set of paints including a wash and a metallic, a medium and a small brush, a water pot, brush soap and a varnish. That is a complete setup and it will finish models to a standard that looks entirely respectable on a table. Everything beyond it is convenience or refinement: a wet palette makes blending easier, a painting handle makes long sessions comfortable, a paint rack makes a growing collection findable, and an airbrush makes priming and base coating dramatically faster. None of those changes whether you can finish a model.
What boxed kits get right and wrong
A boxed model painting kit is a reasonable first purchase because the colours in it are chosen to work together, and for someone who does not yet know what they need that is worth real money. What boxed kits routinely skimp on is the brush, which is almost always the first thing replaced, and they rarely include primer or varnish, which are the two things a beginner is most likely not to realise they need. Reading the contents list against the short list above is the quickest way to see what a kit still leaves you to buy.
An order to buy in
Prime and paint first, because those are what let you start. Add brush soap immediately, because it protects the brushes you just bought. Add varnish before the first finished model gets handled. After that, buy in response to what frustrates you: a wet palette if paint dries on the palette faster than you can use it, a handle if your fingers keep marking the model, a rack when you cannot find a colour. Buying in that order means every purchase solves a problem you have actually met.
Questions people ask about miniature painting kit
What do I need to start painting miniatures?
Primer, a small set of paints with a wash and a metallic, two brushes, a water pot, brush soap and a varnish. That is a complete setup.
Are boxed painting kits worth buying?
As a first purchase, usually. The colours are chosen to work together, though the included brush is normally the first thing replaced and primer and varnish are often missing.
What should I buy after the basics?
Whatever is frustrating you: a wet palette if paint dries too fast, a handle if you are marking models, a rack once you cannot find a colour.