I think you’re getting caught up in wanting a bag, whether it’s right for you or not.
If the bag isn’t suitable for day-to-day use and that’s what you actually want or need it for, then it’s wasted money even if you theoretically saved £250. Wait until you find a bag that you actually love, that’s right for you and your lifestyle and the function you want it to perform.
Keep the money/vouchers and wait until you know it’s right, or truly love the bag.
FWIW I do like the mini Darley Shoulder bag and it’s one that’s on my list to get at some point.