If your clothes dryer is blowing cold air I’d get it serviced.  If it’s blowing hot air then I suspect your issue is a full or partially obstructed dryer vent, and not the need for a new dryer.  While most homeowners clean their lint trip with each load, the dryer vent gets less attention.  It’s recommended the dryer vent get cleaned every 1-3 years depending on the volume of laundry you do.  Lint buildup in vents increases the run time, reduces the efficiency of the dryer, and increases fire risk.

Dryer vent fires damage 13,000 homes in the US each year and cause $97 million in property damage, and one third of these fires come from lint buildup.  This is serious business.  A clean dryer vent reduces this risk and reduces your energy bill via reduced consumption.