Virgin Casino - dumb noobie bonus question

[Splossy]

This place says it will give me a 100% match bonus to £50. It says

"Once you have deposited, we will match the amount up to £50 in bonus funds. These funds are non-withdrawable. To convert the bonus into cash customers must stake an amount equal to ten (10) times their initial deposit. The bonus is converted in full when 100% of the Wagering Requirements are met."
"Bets on Multiplier, Baccarat, Craps, Ten Play Poker, Ten Play Bonus (Video Poker) all variations of Roulette and all variations of Blackjack do not count towards the total stake."

So I'm thinking roulette. I'd need to wager £500 on roulette. So if I make 500 £1 bets am I likely to come out on top or is it really not worth it. Would making 250 £2 bets be much different?

Basically I'm a casino bonus newbie based in the UK. I'm looking top up my poker roll with a bit of easy money. Any ideas would be welcome. Thanks.