Wiring an outdoor room/shed

New build, and had Steeltech install an 8x3 outdoor room/shed outside. Knowing it was coming, I had the builder run armoured cable and ethernet to where the shed was being put in, so the supply is already there. So looking at having a small garage consumer unit, couple of overhead lights, and say a half dozen sockets. Local sparky is dragging on for ages now - was supposed to be done in January, now being told he "might" be able to get to it in April so getting frustrated. Price is going up steadily as well, when he first took a look he said it'd be about a grand or so, last time I spoke to him a fortnight ago he said it'd actually be more like €1,500 since the original quote didn't include materials.

Getting to a point where the wait is driving me mad, so thinking of just doing it myself. (My dad was a sparky so would know enough to install it, and then have a licensed electrician come out and check it). Wife is also keen on the conduit she saw at Steeltech's showroom - anyone know where that can be picked up from? (I asked there, sales fella shrugged and said no idea.)

Any idea on what it should cost?