Just in case, no lint in the filter?

Before purchasing the blower I would take the back off of the dryer, remove the blower cover on the left side and carefully plug in the dryer and turn it on (air cycle if possible so you don't damage the element). You should be able to watch the blower wheel spin if it is working properly.

If you see no problem with it the other thing to check is the lint screen housing to make sure nothing is blocking the airflow there. A lint brush long enough to run the length of it is great for that. Airflow can be blocked by something as simple as a fabric softener sheet sticking over / through the ventilation holes inside the dryer.

Hope this helps.