"GAS" is an acronym for "Gear Acquisition Syndrome". What it means is that you see a new shiny for sale for your instrument and you must possess it. Um. No. No, you shouldn't. A beginner should ask his instructor about any particular piece of gear and stick with it. If you have a decent instrument with a decent mouthpiece setup/bocal/reed, there is no reason to go out and buy something like a $2000 mouthpiece (yes, they are out there) or a custom neck or whatever because it won't make that much of a difference to a beginner AND $2000 can buy an awful lot of lessons. Those WILL make a difference. Your instructor should be your guide, not GAS.