Are the current crop of thermal arm and leg warmers truly worth the investment, or are they simply a marketing-driven fad with little to no practical benefit for the average cyclist? Specifically, what is the actual difference in terms of thermal insulation, moisture-wicking ability, and overall comfort between high-end warmers from brands like Castelli, Pearl Izumi, and Gore, and more budget-friendly options from companies like Decathlon and dhb? Is it really worth spending upwards of $100 on a set of arm and leg warmers, or can a more affordable option provide comparable performance? And what about the supposed benefits of different materials, such as merino wool, fleece, and synthetic fabrics - do they really make a noticeable difference, or is it all just hype?