Scarlets Cut Flower Patch 2022/23/24

Today I started off my new varieties of dahlias - I was missing burgundy colours last year so I got a few new tubers to take cuttings from. I’ve set them up in mushroom trays and they are on a heat mat. Tomorrow I am going to get some horticultural sand for cutting medium. I never have much luck early on in the season but I am determined this year I will get cuttings early!
New varieties ( some I’ve had before and lost)
Sam Hopkins
Josudi mercury
George marston
Barbary Pip
Auroras kiss
Pink candy

My own stock
Mister frans
Polvento kristobel
Dikari superb
Andromeda
Rosemary dawn
Jowie frambo
Josudi Polaris
Jomanda
Marys Jomanda
Moor place
Ken’s rareity
Pam howden
Westerton pearl

So now I am thinking perhaps Im not as old as I look and it is possible to do 6 new beds for dahlias if I can get my cuttings to take. I am thinking card/compost and plabt cuttings straight in.
Compost cost for 6 beds?
Anyone know how to so the maths?
6x30FT?
How thick would i need to go.

Would it not work out cheaper to look at ton bags of topsoil for such a big project?
Sorry can’t help with the costings. No point me looking at such things. The price of delivery would probably more than the topsoil. If they’d deliver at all. But that is exactly what I’d be doing if I could.

Do dahlias like manure? Could you reduce cost of compost by mixing it with manure. You can usually get that for free from stables or farms. If you collect it yourself.

As your flowers are so well known locally. If you asked on a local facebook group about such things you might get some manure delivered   .

So now I am thinking perhaps Im not as old as I look and it is possible to do 6 new beds for dahlias if I can get my cuttings to take. I am thinking card/compost and plabt cuttings straight in.
Compost cost for 6 beds?
Anyone know how to so the maths?
6x30FT?
How thick would i need to go.

So six 6ft x 30ft beds? Each bed would need 425L per inch, so 2550L in total. 

As for the depth, if you are using cardboard then the compost is mostly for nutrition rather than mulch, so I think an inch or two would be fine.

So now I am thinking perhaps Im not as old as I look and it is possible to do 6 new beds for dahlias if I can get my cuttings to take. I am thinking card/compost and plabt cuttings straight in.
Compost cost for 6 beds?
Anyone know how to so the maths?
6x30FT?
How thick would i need to go.

So six 6ft x 30ft beds? Each bed would need 425L per inch, so 2550L in total. 

As for the depth, if you are using cardboard then the compost is mostly for nutrition rather than mulch, so I think an inch or two would be fine.

Wow, I'm impressed by your maths TMTT!

Don't be too impressed, I started to calculate it myself but my brain doesn't work in feet, so I did a Google and used this very handy calculator - https://www.omnicalculator.com/biology/compost

Thank you!
Yes, SC - the delivery is more expensive than the compost/top soil/spil enricher etc.... but small bags are doable - If I do a bed at a time. But I want to work out how much I would need to do tge project.

Dahlias love manure - just have no way of getting it here other than in small bags

TMTT- thanks so much!