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

You need to be respectful of the dealer’s time with your visits without buying anything otherwise the dealer’s radar will go up on you, you might be discussed negatively within their shop, and your experience with them will suffer. No problem visiting occasionally of course but avoid long conversations or demos that distract the dealer from real paying customers assuming that you never purchase. Once the dealer’s radar is up on you, your only recourse is to reset by admitting that you were a time waster, then buy something then and there, preferably without a lot of negotiating and even better if you cheerfully pay at or near full retail. The only exception is if you have a personal friendship with the dealer, but even then be respectful and circumspect about your visits and discussions.

The factors that determine how many visits you can make depends upon the personality of the business as set by the proprietor, the personality of the sales person you get assigned, and your personality.  I had a similar experience as @jasonbourne71 at Lyric Manhattan where I could not get in the door but was always treated well, even when just inquiring without intent to purchase at Lyric Westchester.  There was a high end store in Great Neck NY that actually was yelling aggressively at me because I couldn’t sing along with the bass line concluding I had no ear.  His premiss, documented in a position paper he provided, was that a high end system was of a resolution that permits you sing along with the melodies.  I guess he was not selling me a high end system.  Yet another proprietor in Manhasset down the road apiece let me audition at my leisure, being informative without trying to influence.  You know who got the sale.   Recently, Bill Parish at GTT Audio was extremely patient suffering from multiple calls, never pressuring or putting me off, for over a year,  until I finally purchased a Mola Mola Tambaqui from him.   The key is to be sincere and try to set appointments.  If you are, the seller will let you demo as often and long as you need.  

Hello Dman 777,

As others have opined on your question. Go as often as you wish. You indicate that you’ve been to that store 3-4 times in the past year. That’s not very often but Imo there’s no “max” number of pre-purchase visits before you lay out some serious jack to purchase at that location.  If you feel guilty about multiple visits without a purchase maybe buy an inexpensive accessory if they have something on hand during one of your looking/listening visits. 

As an ex stereo salesmen (many many years ago) it really depends on the situation.  If the store is empty I'd much rather talk to someone about the hobby and maybe learn or teach something.  If the you are taking away time from a paying customer you are infringing on my lively hood which is not OK.  If your respectful of others time and willing to build a relationship it could be beneficial to both parties.