- It's a high value item (I won't waste much time researching items less than $100 unless I'll be using it more than 10% of my waking moments).
- There's enough differentiation in my available options that my time invested in the research will significantly improve my chances that I'll be satisfied with my purchase (like comparing features on a TV, researching specific technology used by specific camera bodies, etc)
First, I'll check the available market and figure out what the range in prices is. (What's the most and least I can expect in the market now.) If this is in line with what I'm willing to pay, I'll continue. I'll figure out which features/specifications are the most important to my satisfaction. If I don't know enough about these specifications, I'll read up on the options and see what is better and why they're better. (Sometimes finding reliable resources tends to be difficult.) Getting an idea on what the cost is for one feature over again is important. Then, I'll narrow it down to two or three models that I'm interested in based on the best intersection between the features I want and the price I'm willing to pay. I research to see if the market is seasonal (will I get a better price during April vs December) or tends to offer discounts or sales on what I'm purchasing. This will help me decided if I should buy now (when buying now is as good as any other time, as it is with technology) or if I should wait for a more opportune time (when sales and discounts are worth waiting for). Then, if I have any ways to pay that give me added benefits with the purchase, I'll briefly consider those options (like paying with AmEx to get traveler's insurance or cash back for a plane ticket versus my bank card which gives me points on flights).
Not sure if you want more detail than that, but that's the gist.
Thanks for your input.