The average cost for a wheel alignment is between $50.00 to $100.00 per axle.
If you have both front wheels and rear wheels aligned then it will likely cost $100.00 to $200.00 for a wheel alignment which is not all that expensive.
Some tire shops will do a free wheel alignment when you buy tires from them but not all of them do.
When you have a wheel alignment the wheel alignment should last 3 to 6 years and sometimes longer.
Most times you should not need to have a wheel alignment done until you get new tires on the vehicle.
If you start noticing uneven wear on your front tires then your wheels are likely not aligned properly and having an alignment done would be a good idea to help protect your tires.
Me personally I will get my wheels aligned every other tire change which is usually every 10 years unless my vehicles front tires or rear tires are wearing out unevenly.
Most mechanics will typically recommend having a wheel alignment done every 2 to 3 years but unless your tires are wearing out unevenly then there really is no need to do the alignment that often.
But it certainly is not gonna hurt anything except your wallet to have your wheels aligned as often as you prefer.