"30 bucks? Sure, that's kinda expensive for a movie, but if you think about it that's really no more than 5 Drinks in a Bar."
Basics
Drinks in a Bar are an extremely useful tool for anyone who drinks socially to rationalize spending money. The idea is is that drinking in a bar or a club is a monumental waste of money that you do every Friday and Saturday night, so by comparing that to what you're trying to convince yourself you can spend money on you can justify anything. I just went to Europe for several hundred Drinks in a Bar. Once there I drank in many bars.
Advanced
Of course it usually helps to use a number of drinks you could conceivably drink in a bar. Just telling yourself buying that house on the corner with the nice lawn would only cost you twenty thousand Drinks in a Bar is, well, useless. That takes a bit more effort.
"Well, if you think about it, this only cost the same as a few hundred Drinks in a Bar. You said you wanted to stop going out to drink so much anyway, so now you can do that. This is better than going out drinking every week anyway, isn't it?
"Well, if you think about it, this only cost the same as a few hundred Drinks in a Bar. That's where all your money usually went anyway, so now you won't be able to do that. Buying this will force you to quit drinking. It's for your health!"
"Well if you think about it, it only cost the same as a few hundred Drinks in a Bar. If we had spent that on Drinks in a Bar, we'd likely both be dead. If we hadn't bought this, we'd both be dead."