At your budget you are really only going to get a base model bike if you buy new. EMTBs are expensive.
It's hard to say buy this or that because of the weird position the bike industry is regarding stock and also personal preference plays a huge part.
If I were you, I'd work out what size bike...
There are quite a few companies offering good hardtails for that kind of money. Stock is often an issue though.
A quick google turned up a 19" (medium?) Cube in Colchester. linky
If you have the cash on hand and are not looking for a specific bike, you should be able to find a decent hardtail...
If it's this one, it looks a bit rubbish for the price.
If he's not riding proper MTB trails he could get a much better spec'd hardtail from a much better brand for that kind of money.
Something like this
There's a danger than people will end up thinking a 'this is what you can get away with if you understand the risks' solution and a 'this is how you're supposed to do it' solution are the same thing.
EMBN should not have put that video out a tutorial.
Yep, just patch it up. If you were planning a big day out, miles from anywhere you might want to stick a new tyre on, but if it's just laps close to home/car I'd 100% risk a patched tyre.
I predict a large percentage of those who hasn't used a chain wear tool will post a thread asking why their gears are slipping in the smallest cogs at some stage.