Good advice from @dunnyrail regarding pricing. As regards how to sell it, it depends on how big your collection is. Selling on here is good as you are in the UK and so are the majority of members so shipping is easier (can't use "buyer collects" at the moment due to lockdown). If it is LGB stuff that is likely to attract the biggest audience. You are limited to "buy it now" pricing but there are no fees if you use paypal family and friends. You can't sell too much at a time though as you might "flood the market" and if it does not go quickly I don't think members often look to see what is still available, so you have to be prepared to manually "bump" it. Otherwise ebay but as @dunnyrail mentioned and @ebay mike in another thread it's not a good time to try and get money from other people's pockets - it's a "buyer's market" at the moment, so either use "buy it now" or make sure you have a reserve if you got for "auction". Don't underestimate the time to create a good listing whichever route you use and time and materials for packing.