Creating an NPC

I want to create an Npc that allows level jumping. I want it to be like a trainer but when you pay for the item (usually a spell) you get levelled up. I want there to be a few options eg

Lvl 10-20

Lvl 20-30


All for different amounts of gold.

I thought that making this a quest would be easier as I can easily set a minimum and maximum level but i didn’t think it would look as good. For the levelling itself I need some advice. Is it possible to get an NPC to run like a gm command eg .level 10

Or would I have to work out the xp required and make it a quest rather than a trainer so that the xp levels them up.

Ideally I want a trainer Npc that you can visit to reach certain levels


Level 10 cost 10g

Level 70 cost 200000g or something expensive like that.

I also want it so that once you have passed that level you cannot purchase the “spell”

Anyone understand my idea and know how I can go about making it??