You probably can find marginally cheaper, however they are very fast and efficient, plus the postage is free. They send a pre-paid padded envelope for you to use next time, which is great. They also send the blades back in a plastic holder to keep them safe and to send them in next time. They put a list in as well, stating if anythig needs doing or ticking them off as fine if not.
I've used them for blades sharpening and you send them, they get them and either do them then next day and send them back asap. Mine went blunt halfway through clipping early Monday morning for hunting the following weekend. I sent them that day, got them back on the Wednesday or Thursday (not sure which) and finished my clip. It meant we didn't have to go hunting with a half bald patch on my horse's bum!
I also had my clippers serviced by them this year and they were very good with timings.