Tweeks, back when it was Demon Tweeks dealing with motorcycle parts, has always been like this. They keep limited stock and they buy it in when they get enough orders. You can have stuff in two days but sometimes tug can wait ages. It’s why their prices fluctuate wildly. I once ordered a pair of EBC discs for a Honda and when they arrived I’d been charged almost double what I’d been quoted, from £160 to around £300. Apparently it was because I’d been dealing with one sales guy (it was by phone back then, mostly) and got a deal, and when I’d confirmed the order it was with another guy who stuck to the list price. Told them I’d return them for a refund and quickly got the deal price back. Dodgy tactics all round.