I know there was quite a bit of concern about the recent price jump of Solgar methylcobalamin 5,000s to about £18. I'm posting this to let anyone affected know that they're currently back on Amazon UK at £12.58, with free postage if you spend £20.
The website uk.camelcamelcamel.com/ is fantastic for getting email alerts whenever an Amazon-sold product you've registered you're interested in drops to or below the price you've said you're willing to pay. That's how I found out the Solgar was back in stock at a more reasonable price. (As far as I'm aware, giving them my email address hasn't resulted in spam.)