Why do gardeners charge sooo much postage? £7.75 just for some bits and bobs, even just a hozelock connecter would cost £6.50 postage so the price would be just under 12 quid. 
Mainland UK postage on items up to £10 in value costs just £2 by Royal Mail, over this we switch to FedEx which costs £7.75, Orders over £45 are provided with no courier charge.
With small items there are two options:
1. Order below £10 worth and pay just £2 postage - sometimes worth splitting the order and paying just £4 for up to £20 orders.
2. Order above £45 and pay nothing for postage.
3. Alternatively on some light but costly items (above £10) it is worth ringing the office and seeing if the item can be sent cheaper by Royal Mail - the website can be limited as to the postal calculation options. This wouldn't have the same insurance as the FedEx option though.