Of course I am not stopping you, but sometimes the cheaper shed may not last for many more Easters, so best to spend that little bit more and go for Pressure Treated wood.
The main online providers are very competitive at the moment but I doubt you will get your shed in time for the break to be able to start pottering around in it..
If I was buying then, these ones have caught my eye as they are good for what you get, as sometimes if you don’t have the time/effort/skills
7’1×6’10 (2.16×2.07m) Larchlap Pressure Treated Overlap 77PT From ShedStore.
Heavy Duty Shed 8′ x 6′ From taylors
Of course the big DIY retailers are also trying to get your Easter Cash as well