My general rational for justifying a purchase is: How much will I use it?
For example: When I bought my Garmin Watch, it was a pretty good bet that I would wear it every time I ran and I generally run often. Therefore, if you divide the $250 price tag by the 260 or so times a year I run; you get less than a dollar per use. And that is just for the first year. I have had the watch for many years, so by now we are looking at pennies per use. Not to mention that I am now biking a good bit and I use the watch for that too. All in all the Garmin was a good purchase that did not sit in a draw or closet after I lost interest.
Since I picked up the Triathlon bug, everyone has told me I will need to get a wet suit for the race or else my nether region will take a trip back in time to when I was a 2 year-old-boy (I know what you are thinking...and it IS a long trip). When I balk at the prices and complain that I have already bought a bike, they say, well you can rent one. I'm sorry, but I have never been a fan of renting clothes; I make an exception for a tux and bowling shoes (although for a while there I actually owned my own bowling shoes...but that is another story).
So I started shopping to find the best deal I could, but I also wanted a good suit. I tried to get a 2007 close out deal, only to find that I could only do that if I was 5 ft. 6" and 150 lbs. I even tried to squeeze into a size large...let's just say that I'm glad no one had to witness that.
Finally, my 2nd favorite store REI to the rescue (Don't tell Best Buy I am seeing someone else). See this is where I bring this post full circle. I ordered my Garmin Forerunner as soon as they came out. I did this because I ordered it through REI to make use of my dividend check (REI is a co-op and gives you a check each year based on how much you spend there...basically a brilliant way to make you spend more money there) and to use the annual 20% off coupon before it expired. Well looking back on how well that worked out (I got a great deal on something I love and use all the time) I decided to apply my dividend check and 20% off coupon to my wetsuit. I finally bit the bullet and ordered the suit (to be delivered next week).
However, I can't fathom getting much use out of the wet suit at all. I mean sure, I plan on doing a few triathlons and of course there will be open water training, but still. Maybe I can just wear it around the house...can you imagine me answering the door to the UPS guy in my wet suit. Or better yet, maybe wearing it out for drinks at the local bar....