Too many people seem to believe that all computer equipment is essentially the same and that you can buy strictly on price. In our experience, that's a risky approach because the computer industry is riddled with manufacturers who ship buggy products, ship products that they quickly abandon, fail to provide competent customer support, or deliver proprietary products that lock customers into expensive upgrades.
For that reason, we suggest you follow a policy of keeping track of the manufacturers whose products serve you well and whose products serve you poorly. Knowing that lets you return to the former and shun the latter. You might save a few bucks buying strictly on price; we've found 10/100BASE-T network interface cards for as little as $13, which is admittedly a lot less than the $40 that we typically pay for name-brand adapters we've proven in our networks.