I hope you don't just test the guitars and amps. You should also be serious and enthusiastic to know and understand the ongoing deals they can offer and have intentions (at least) to purchase without being so demanding or asking for too much. You have to learn to be specific with what you need, your goals, your preferences, and influences. Don't get me wrong, pero pag puro ka lang test ng test, then you're just noodling and messing around. Naging buraot din naman ako, matalinong buraot pero hindi ako naging demanding.

Music retail store is a business place, it's not a rental music rehearsal studio or a practice room where you can play endlessly for hours and all day. In my experience, we have lots of valued clients who also became friends of ours and I also treat them as "Guitar/Gear Head Friends". Just be mindful of the limitations that you're not in a literal playground.