How many times can u visit a hifi store before it annoys the store if u plan on a purchase

I think that is up to the store / salesman more than you.  Some buyers take more visits than others.  I was seriously inquiring at a well know store in Delaware when the salesman decided to stop returning my calls.  I moved on and bought my dream system elsewhere.  I thank him for that!

It’s a store. It’s there for customers.  Go as often as you want or need.  The hifi police will never know!

There are plenty of people that have no intention of buying and these people don't care how much of your time they consume. 

"Knob twisters"

"Tire kickers"

"Gear gawkers"

"Lookie-Loos"

Good sales people know who you are and see you coming. Don't be surprised when they don't return your calls. It's YOU who is the problem not them.

I always bring cookies for the crew....each time.  Or something.  It should be a bit social.  The exchange meant to be enjoyed, not endured.  I've even taken microbrew.  But then, that's just me.  Cheers

Completely dependent on the store and your personality.