As Don said, they will ship any amount. However, to justify the cost of shipping, browse around and buy some spares that are always worth keeping.
For example, get some male bullet connectors and some of the female bullet couplers (single line couplers, 4-way couplers, etc). They also sell the proper Lucas wire color codes so maybe pick up some wire to fix and/or replace a bit of the wire that is bound to be hardened in your car's harness (i.e. green/blue for the temperature sending unit, white/brown for the oil pressure switch, maybe some of the red/green and such wires for the running lights and turn signals....) Browse the site. I'm sure you will find lots of interesting things worth adding to your order.