Sherley, depends what he is into but here are some ideas
Train table not on offer (aside from the 3 for 2) but very cool present
https://www.argos.co.uk/static/Product/partNumber/3498468.htm
Charley bear teddy half price
https://www.argos.co.uk/static/Product/partNumber/9151015.htm
Fireman electronic book 1/2 price
https://www.argos.co.uk/static/Product/partNumber/9087220.htm
Leapfrog touch magic bus half price
https://www.argos.co.uk/static/Product/partNumber/9087653.htm#pdpProductReviews
Massive tub of mega bloks half price too
https://www.argos.co.uk/static/Product/partNumber/9076846.htm
Thomas the tank engine 25% off
https://www.argos.co.uk/static/Product/partNumber/9152894.htm
Like tykes car carrier 50% off
https://www.argos.co.uk/static/Product/partNumber/1165573.htm
Little people zoo train £10 off
https://www.argos.co.uk/static/Product/partNumber/9155626.htm
fisher price wheels, loops and hoops half price
https://www.argos.co.uk/static/Product/partNumber/9087921.htm
thomas and friends deluxe starter set mega bloks
https://www.argos.co.uk/static/Product/partNumber/9157765.htm
Cool remote control car
https://www.argos.co.uk/static/Product/partNumber/9129580.htm
Some duplo sets
£7 off https://www.argos.co.uk/static/Product/partNumber/3974432.htm
1/3 off https://www.argos.co.uk/static/Product/partNumber/3974384.htm
1/3 off https://www.argos.co.uk/static/Product/partNumber/3974360.htm