Can a cheap angle grinder be used to cut concrete and ceramic tiles?
In most cases the cost is directly related to expected durability. In expensive commercial/professional grade tools, parts spin on ball bearings and motors are more powerful. They are designed to run allday every day at maximum speed where time is money. Home owner grade tools typically are designed to be used for brief periods of time and at less than maximum performance levels for the majority of their use. They contain less powerful motors and parts spin on bushings instead of bearings. In most cases they will last a long time as long as you respect the design limitations of the tool. If it starts to get warm while using it stop work and let it cool a while. Don't force the tool if it starts to bog down back off the pressure and let the tool do the work. I have a 10 year old $30 grinder that I cut over 100 slate floor tiles with and it is still running strong.