In the UK, you have quite a few options.
PADI- OW course will run you about £300, but at this time of year you need to do it in a drysuit, so you're looking at £400-£450ish. Can get the course done in 4 days (which isn't necessarily a good thing). Most places include all kit hire in the price. Qualified to 18m.
BSAC- Club based (
Learn to scuba dive in UK and snorkel dive the BSAC way - there is no better!! You have the BSAC fee (£55), the club fee (which varies from club to club), plus the possibility of other fees (equipment rental, fees for the Ocean Diver manual which is about £40, other misc fees the club may tack on). The training will be longer than a PADI OW course, but if it's a good club, it will be 2-3 months (theory, pool, OW dives), and the training will be quite thorough. Downside is you will be expected to get your kit pretty sharp-ish. You're qualified to 20m, can use 32% or 36% nitrox on air tables, and most of the time it's done in a drysuit
GUE Recreational Diver 1 course (
Recreational Diver Level 1 - Nitrox diver | Global Underwater Explorers) There hasn't been many GUE Rec 1 courses in the UK (I know of 3), but there is a very large, active GUE community (most people have come up through PADI/BSAC and taken fundies but that's another conversation) in the UK (check out the GUE-UK facebook page). The course itself will take at least 5 days (i think), and I'm not 100% certain on the price as each GUE instructor sets their own, but they tend to be around the same. The course qualifies you to 21m, using mainly 32% nitrox, but also air, a drysuit if you chose, plus DSMB deployment. There are 4 GUE instructors in the UK and their contact info can be found here(scroll down to England):
GUE Instructors | Global Underwater Explorers
The GUE kit configuration is quite specific, I think most of the instructors can provide kit for training besides the basics like masks and fins. And there are enough of the GUE lot kicking around to lend kit to a newbie until he/she can purchase their own.
Note: I am an active member of GUE-UK, a working PADI DM, and a member of BSAC. I don't really have any loyalties