I love a handbag thread 😃. £1k won't get you a decent sized luxury brand handbag from the original stores but have a look at brand new designer handbags on eBay. Don't go for the brands that are always counterfeited (Gucci, Dior etc). And ask the seller lots of questions, look at what else they're selling to help you suss out if the item is genuine.
I'm currently in love with my Marni Trunk bag in medium. Can be dressed up or worn with jeans and trainers.
The Prada double zip camera bag which has interchangeable leather and fabric straps is a perfectly sized bag for everyday use.
I have my eye on the Loewe puzzle bag but can't stretch to the high value it holds in the 2nd hand market.
For evening bags I have a couple of Bottega Veneta Olimpia bags in small and medium. I think they're the next best thing until I can afford a Chanel 