You wouldn't spend $100 for an airplane tx would you? It's the same with cars. You get what you pay for. You could always pick up a 2nd hand radio on here for short money instead of buying a new, but lesser quality radio.

Or,

make sure the antenna is not damaged, is pulled out of the antenna tube, there is no dirt in the rx, the tx antenna is pulled out all of way( pretty basic, but sometimes we miss the little things) .

If it's an AM radio, you might want to upgrade to an FM tx.