Is it easy enough to change the tap & waste fittings of your bathroom instead of buying all new - because its really only the taps that need replacing

What do you think by saying "..buying new bathroom..."? Please, be more specific...

I mean instead of buying a complete bathroom suite is it easy enough to change the taps & wastes

Well, if existing cabinets, toilets, sinks, tub and shower fit your style, then yes, it is easier, and cheaper, to purchase just new drains, faucets / trim, and upgrade your existing faucets and valves to present styles.