As long as you have a local place that can do refills it takes about 10mins. I have found a one near me that can do my 2kg one for Ā£10 so that seems pretty reasonable. If you buy a jbl one that has to be refilled by a jbl stockist. Kiddy is a fairly large town so I would think their is something near you.
A good budget CO2 kit is the deltec one. It's Ā£100 & that includes eveything including the solenoid too. Comes with 600g disposable but they sell an adaptor for Ā£13 to convert it refillables.
Great area, used to Holiday at Wilden Top, near hartlebury castle I think, with my family every year & I loved the whole area. Do thay still have that funfair type thing at stourport near the river. I can always remember their used to be a big model railway their that used to be so much a go to control? Especially good area if your a fisherman too!!