Filing a trademark in the US without breaking the bank is quite possible. The cheapest way is to do it yourself online through the United States Patent and Trademark Office's (USPTO) website. The fee ranges from $225 to $325 per class of goods or services. However, the process can be complex and time-consuming, so some opt for affordable online legal services like LegalZoom. Still, remember that while these methods may save you money upfront, mistakes can be costly in the long run.