I like Dahlia, too!
I usually start them from seed, and as soon as I see the tubers available at Walmart/Garden Centers I buy a few packages and start them in pots in my greenhouse to give them a head start.
A favorite from seed is called ‘The Bishop’s Children’ - I know - weird - but the seed was bred from ‘Bishop of Landlaf (sp?) which is a gorgeous dark-leaved Dahlia that’s been around for-ever. Seed Savers used to carry them - probably still do.
Since I buy inexpensive tubers, I don’t bother with the digging and saving tubers from season to season.
Seeds. Not available now, but will be in spring, again, I’m sure:
https://www.johnnyseeds.com/flowers/dahlia/giant-hybrid-mix-dahlia-seed-3397.html
I bought a package of dahlia seeds this spring and none of them germinated. It was VERY disappointing!
I’ll keep an eye out at Walmart for tubers. I didn’t know they had them. They had seed packages out in the main store near the doors to the garden center, so I really didn’t look around very much. I usually head straight for the bird seed & this year, the peat pots!
Park Seed has Bishop’s Children Dahlias. Since you like them, maybe I should try them next year. 😊