I've never used Gumtree, but I've seen a secondhand amp I'm interested in for £800, a fair price. Through Gumtree I've contacted the seller who says it's 4 years old, in mint condition and he's selling because he's upgrading. Because of Covid I'm not able to audition it and Gumtree suggests you use a courier rather than personal collection. Is there any protection for the purchaser if what arrives isn't what was promised (and paid for)?