Learned that lesson the hard way too, but with a different gadget. Bought a $15 wired remote for my old Canon and it did everything the $70 brand name one claimed to do, just without the fancy box. The thing people miss is that intervalometers are dead simple tech, it's just a timer that trips the shutter, so paying extra usually gets you better build or a nicer screen, not better photos. The real trick is making sure your camera accepts the cheap trigger's plug, because some bodies use a weird proprietary port and that's where the budget ones bite you. Also grab a spare coin battery for it, those little watch cells die at the worst time in the cold. Stack your frames in something free like Sequator and nobody can tell what remote you used. Save the money for glass instead.