The money goes on the speed and efficiency with which they will problem solve. All the awkward things or stuff that you want to use right up until the day. House plants, anglepoise lamp, toaster, clothes airer, the vacuum cleaner, the garden tools. Should you pack that in a box or is it too big? What the hell can you pack it with? How do you pack this item so it won't spill? Or this one so it won't damage something else, or get damaged itself?
I've never used packers, and making all those decisions, again and again, for days on end while you get through it all, is exhausting and time consuming. Our last move, I had some random very last bits left which the removers threw in a box for me. The speed and efficiency with which they just made things disappear was quite startling. I had complete decision fatigue by that point.
The repetitive stuff (clothes, books, crockery) is very easy. The awkward stuff is very VERY hard. Does a microwave go in a box? The baking trays are too big for the other kitchen boxes, what else to pack them with? How do you pack a saw? Is a box full of cushions too light, should you save them for packing around other things as padding? How many books makes a box too heavy? Where to pack the remote control so you'll remember?
You can solve these problems yourself, but professionals have solved them so many times that they know the best answers and they aren't even problems any more.
Now, by the time I've mulled over all this and hit send you've probably answered saying you've already convinced them.... 🤣