I've had a hot tub for about 4 years and I use it about 1-2 times per week in the summer and and 2-3 times per week in the winter.  
 
I will never go without a hot tub again.  I put an outdoor speaker with volume control out there, and it's awesome to have a couple beers and hang out there with friends and whatnot.
 
The maintenance of these things is about the same as a fish tank.  I check the chemicals each week with the little tester strip.  Usually it only requires some Bromine.  And I'm good to go.
 
I drain and fill it each Fall and Spring.  And I spend about $75 on chemicals every 6 months.  Get them from 
www.hottubessentials.ca
 
As mentioned, you're either a hot tub person or you're not.  And you are correct in it costing about $30 per month in power.  To me that is absolutely worth it.