Found a new source of hi-vis today!

[Arizahn]

Went to our local B&Q to buy some compost. They had hi-vis tabards in stock, reduced to clear. I think they were down to around £2 each, so might be worth having a look if there is a sale near you. Didn't have time to check, so no idea if they meet the level needed for riding, but they looked fairly luminous from where I was standing!
<suspects she is the last one to discover the above tabards>

 

[FinnishLapphund]

On their website I can only find that they have the "normal" high-visibility tabard/waistcoat in child sizes B&Q Childs hi-vis waistcoat X-Small.

But they also have this bodywarmer, where you can choose if you want to wear it with the black side out or with the high-visibility yellow side out JCB Reversible bodywarmer Black-Yellow.

 

[Arizahn]

Might just be here (northern ireland) then, ours seems to be having some sort of massive clearance of everything at the moment. Hi-vis bodywarmer sounds cosy though!