A you sure that the buds are in fact new buds or spent flowers or have you been dead-heading on a regular basis which will make the plant keep on flowering? I usually leave my Dahlias until most of the foliage has died down. Lift them and knock off most of the soil and leave to dry out in greenhouse or shed. Then remove any dead stuff, label them if you have different colours for next year. Store in dry sand, dry compost or wood shavings in a frost-free environment, perhaps under a bench in the garage until the spring.

They look like spent flowers to me. Buds are round, instead of oval, and face sideways, instead of down.

yes they look like spent flowers too. squeeze them if very hard and round they are buds if squishy then they are spent flowers. I also leave them until the frosts 'knock' the foliage back.

Thanks folks I squeezed one and squishy I was told to just wrap in newspaper then store in box not to waste money on sand or compost is this ok?

well if there is plenty of paper around them yes. sawdust works too, that's what I use. we have plenty as we look after a rabbit now and again.