Rent a car for 3 days & do all the trips yourself... much cheaper & gives you loads of flexibility.
Lanzarote is basically the size of Wicklow so 3 days is plenty to explore the likes of
Timanfaya National Park
Teguise Market
The Cactus Gardens
El Golfo
Mirador Del Rio
Cesar Manrique's House
Jameos del Agua
Guinate Tropical Park
There's also a pretty good shopping centre near Arrecife called the Deiland