I bought a decent 7" tablet in Sainsbury's about a year ago. It was reduced to just £59.99. Although their normal prices are quite a bit dearer than that, they still have some good products at reasonable prices. So perhaps you could put your £40 towards a tablet?
Alternatively, if your TV isn't 'smart' and/or you'd like to be able to receive channels like GOLD, Sky 1, Sky Arts 1, etc but you don't have satellite TV, Sainsbury's sell Now TV boxes (which provide you with lots of TV extras via your internet connection) for around £20 (which includes 3 months access to lots of extra channels if you opt for the 'Entertainment pack - thereafter you pay £6.99 per month if you want to keep those extra channels but there's no subscription commitment and the box still gives you catch-up TV services, together with Youtube, etc).
Still no good? Remember that the larger Sainsbury's stores have their 'TU' range of clothing. You might find something there.