I’d consider the recipient and the occasion first, then look at the presentation and delivery arrangements. A bouquet of 501 roses is obviously a very large gesture, so it should fit the person and the event rather than being chosen only because of its size. I was comparing large rose arrangements and found https://mireya.ae/catalog/dubai/501-roses/. Looking at an actual example helped me understand the scale much better than simply imagining 501 flowers. I’d also confirm the delivery date and address in advance and check any relevant delivery information. With something this large, planning ahead can make the whole experience much less stressful.