Which markers to buy?

When working on this painting I was thinking a lot about which markers I do need and where I should get them. This is hilarious because I really have a lot of markers. But of course I am watching Youtube Videos about all kinds of markers which come in sets and are unbelievably cheap and have all kinds of colours. And of course it is very easy to order at Amazon - you order them and get them in two days. 

However: The only time I could not resist was when I bought of set of markers with pastel colours. In general I go to an art store, look for the colours and markers I need and buy one or two or sometimes three. I've got three reasons for that:

• it is very nice to go to an artstore, to touch and try out markers. 
• There are some marker brands which are also cheap and can be bought locally.
• I do not get a lot of markers which I will never or seldom use, I just can get the ones I need.