I just bought a Umbro Mini Goal. Children's Football Goal (100 x 70 x 50cm) for my boys in store for only £4.00. Ideal for small gardens.
Football goal size 100 x 70 x 50cm.
Weatherproof net and 4 ground pegs
Constructed from weather resistant robust plastic tubing (45mm diameter).
Attractive Umbro graphics
Easy to assemble
Amazon have them for £8.99