If like me you buy a 2nd pair of trusers with the suit you buy to make it last longer then M&S have an offer at the moment where if you buy a suit, you get a 2nd pair of trousers free. Savings from £49-£99 (I think that is the most expensive trusers)
I have just used this and combined it with £10 off voucher as well as free delivery over £150 for specified day to get a sartorial suit with extra trousers for £189 instead of £278.
Not sure how long the offer lasts.
First post so not sure how to get picture
Don't forget Quidco or similar to get more discount