My personal view is: never knock a man when he's down! Even a child needs a hand to get on its feet to start with.
I work full-time as well, and only have the evenings and the weekends to spare on the plot. So I have thought really hard about whether it is a viable proposition or not, and decided that (with a little help from my friends) I can - and will - make it work!
So, if needs be, get sombody to dig it over for you initially, but then make sure that it's you that carries on from that point. I'm sure you'll find plenty of advice and help from the others on your allotment (or on here).
Best of luck matey!