Just wanted to ask if you think aquarium starter kits are worth buying for a newcomer to the hobby, or if it's worth buying equipment separately?
I've heard that starter kits can be a little unreliable (heaters for example) and just wondering if it's worth buying a starter kit along with upgrading some equipment, or are there any starter kits out there which are currently great. If not, what would you want to see in a starter kit for it to be worth buying?
It very much depends on the kit in question. Small starter tanks such as those typically offered by general pet stores and only 20 Litres or so are unsuitable for fish. Others are better.
As a starter, you'll want 60L minimum so I would look at something like the Juwel Rekord 600. It comes with everything you need and has reliable heating, lighting and filtration. If you can go bigger then do, as bigger tanks offer more stock choices and more room for error due to a larger volume of water.