I can't seem to figure out how to buy an invisibility potion in a shop that has both detect and invis. I try, buy invis I get detect, I try buy 2.invis I get can't afford 2 of the things at the top of the list. I try buy 7., get I can't afford 7 of the things at the top of the list. I think that's all I tried but a little help here would be appreciated.
Or, do I need to turn off autoaim and try it but typing the whole word?
roll an invoker.
har har har
Never mind, re-read your post.
EDIT: After trial and error, use the ' around your word to aim it at the right potion.
So, buy 'invisibility'
Or just buy from the elixir man.
Or roll a DK.
Or find free invisible potions/objects-that-once-eaten-make-you-invisible.
har har har, everyone is so helpful. I know about the elixir man but when you are in Val Miran he's a long ways away. I know about the objects too....That is why I asked about "shopkeeper potions"........har har har.
Well, if you're in Val Miran, you're not far off, eh? 
If I am in a hurry and want to go invis quickly so someone can't see me sneaking up on them, I'd like to be able to just bam buy it there. Again, thank you all for your help it is appreciated.