Choose wisely - we have had numerous customers who have purchased sub standard products - that cannot be installed - they are expensive garden ornaments.  Make sure you purchase your shower, vanity tapware from a reputable company - so you have someone to go back to if you have any issues.  You should look for a company who is stable in the market & has been around for a while to have credibility.  This goes for buying your goods as well as the tradesmen you choose.  There are many web sites that sell second hand - or extremely cheap goods - buyer beware.