Since you mention $80 and bellow you restrict yourself to the Entry Level Wireless.
Almost all of these units (including Router?s, Access Points, USB, PCMCIA, PCI. Etc.) are using OEM Radio units that are yielding 30-33mW and manufactured by few OEM providers. In other words the inside of most units is around the same Radio.
Speaking of the Brand names, there might be some differences in driver?s stability and quality of Antenna.
It is impossible to direct you to a specific precise product since low QA deem it so that even within specific model number it is a matter of luck, and there might be a good or bad units.
So what a person should do.
In a general sense, of the Entry level Wireless devices, the Wireless line of BuffaloTech. Seem to offer good solutions. (
http://www.buffalotech.com/products/wireless.php ).
Buffalo seems to pay attention to QA and Windows compatibility; many of their units offer a replaceable external, Antenna and High Power RF output. However it comes with a price, the hardware is slightly more expensive than the average entry level Wireless, and it is not available at heavy discounts.
Might be that your specific card is bad, so borrow, get, buy returnable and try another.
Otherwise.
The best Method to Extend Wireless Coverage depends heavily on the Specific Environment.
Look at these pages they describe most of the options that are within the means of Entry Level users, and choose the one that fits you environment best.
Link to:
Extending the Distance of Entry Level Wireless Network.
Link to:
Wirelessly Bridging Home / Network.
Link to:
Hi Gain Antenna for Entry Level Wireless.
In general, the best Method involves using multiple units connected with wire to the source.
Or WDS (
Wireless Network - Configuration Modes. ) system using Hardware of one Brand across the board.
:sun: