Yup. The downside is that you receive only about 30% of a new items price; also based on condition, provenance, collectibility, etc. IIRC, GC uses a standard search function from Reverb or eBay, as well as their own website that calculates the lowest price your item sold for within the past 6 weeks. GC typically pays out to the seller the lowest price minus 25%. However, it's necessary to note that a brand new item MSRP brought in for sale typically is relisted and posted on GC's website at 55 to 60% of MSRP. The seller receives 25 to 30% less of that relisted price.
In only conditions where I might need to raise a lot of cash in a hurry (expensive car repair, dental surgery) would I sell to GC. Other times, my sales are calculated as one-in-one-out purchases/sales and my pref is still eBay for it's comparative reliability. Only more recently have some buyers had buyer's remorse and returned the items within the 30 day window. Even though my sales list as all sales final, the buyer still has the advantage of being able to return an item he can't adjust to or realizes it's not for him.
More recently, I've discovered that one can save a healthy amount of money simply by avoiding online buying over several months time. It might be wise to save up for desirable instrument purchases (used, of course) or new with warranty for electronics. All electronics in my household have about a 10 to 12 year lifespan before they need replacement; UPS backups about 5 to 6 years. Makes sense to save money over time to replace non-functioning electronics when they sputter and fade rather than sell gear that you treasure anyway.
