Of course if saving money is your only reason for buying then I will agree with you.
If
@MrGrumpy has made past purchases purely on the basis of price, that might explain why he ended up with a duff pair of shorts from
Decathlon. Fortunately, in this case, he's got high quality kit
and a good price. It's your downer on Halfords I really don't get - dismissing it as a "car accessory shop" overlooks the fact that it sells some very good bikes and kit these days. You might not get the level of advice and service that you'd get from your LBS, but that's generally why you pay a bit more at your LBS.
And I'm still not sure on what basis you're recommending Impsport as an alternative. Is their stuff good quality? If you say it is, I'll take your word for it, but I can't get beyond associating them with ugly novelty designs. And not forgetting that GB national team jersey from the late 90s with the lime green splash...
Tbh, if you want to recommend good value, British-made cycling gear, several other brands spring to mind ahead of Impsport - Lusso, Howies (as mentioned by
@Elybazza61) or Endura, for example. As for alternative places to buy from,
probikekit.co.uk is a good one in my experience because they often have high quality shorts and jerseys from top brands (such as Sportful) at very good prices - perfect, as long as you don't mind wearing last season's pro team kit.