Heat and humidity decide more than the price does. Here is what holds in an ordinary flat and what will not, whatever you paid for it.
The question we are asked most often is which flowers last, and the honest answer depends far more on the room than on the stem.
Start with the room, because it decides everything. An air conditioned bedroom at twenty five degrees is a different world from a living room with the windows open at thirty two. In the first, a good bouquet holds six or seven days. In the second, four is a fair expectation and two is normal for the softest flowers.
What holds well here. Chrysanthemums, which are unfashionable and outlast everything. Carnations, which are better than their reputation and will go ten days. Orchids, both cut and potted, because they are built for this climate. Anthurium, which looks like plastic and keeps for a fortnight. Most foliage.
What does not. Hydrangea, which wilts within hours of being warm and does not come back. Anything with a very soft petal. Roses are in the middle: excellent for about five days in air conditioning and noticeably shorter in a warm room, which is why we ask where the flowers are going before we suggest them.
Three things that make a real difference at home. Cut the stems again when you get them, at an angle, and do it under water if you can be bothered. Change the water every second day rather than topping it up, because in this heat the water is the thing that spoils. And keep them away from the fruit bowl, which sounds like superstition and is not: ripening fruit gives off a gas that ages flowers quickly.
Last, do not put them under a fan or in the path of the air conditioning. Moving air dries a petal faster than heat does, and the spot people choose for flowers is almost always the spot with the most air moving through it.