Its a very difficult situation and as Ziggy says - the shops arent enjoying it either.
Were having to cope with prices rises on various products almost daily now - many of which we arent informed about until we go to order the product. The first shimano price rise from Madison we were informed of about 2 weeks in advance. The latest one which happened late on Saturday we didnt even have wind of (perhaps because of its scale to stop mass stocking in at the lower prices - i certainly would have, and have with companys who have let us know when prices are going up and what too i.e mojo on 1st feb).
Im in similar position from the other side. On saturday I quoted and took a deposit a custom build running full XT price matched to CRC - usually never a problem at all. Checked all cost prices and it was fine to do. First i heard of any new rises was at Core on Sunday night but didnt really take much notice. Came back on monday to order the stuff i needed to find it had all gone up.
Luckily had a decent amount of the kit i needed in stock already, but even with that and the leeway on the other prices were barely breaking even on the build - but managed to maintain the price for the customer.
Its a real problem, even worse online, can only suggest in the coming months for anyone after slx/xt/xtr to find the cheapest price, phone and check availibility and go from there, otherwise this problem is going to crop up more and more.