Welcome to the forum Steve.
You only need something to spin a bit of wood up, and one chisel (1/2 gouge ) sounds like you have got the spinney bit coming already.
For pens you will only need one kit, I would suggest a slimline pen to start with, as they are cheap and if you make a c@€k up of it then it's not the end of the world.
You will need something to sand the pen down and polish it up, standard friction polish is a good starters.
Get some cheap bits of wood, fire wood will do. (The packs you get at the petrol station ) you don't even need a mandrel.
Follow a few tuts on pen making then you are hooked. ..
In simple terms you don't need much more than you have already.
I agree with all the comments of buy the best you can, but you don't need too to make pens.
Where are you I the UK, there might be someone close to you that you can pay a visit and show you how simple it is ...init...
Oh and by the way, you don't need a chuck, just a dead center and a live center to start with..
Oh and you don't need a pen press, just a vice on ya bench..