Welcome to AK. Goodman speakers are a well-regarded but less popular brand for those who like their music delivered using tube amplifiers. The speakers tend to be very efficient and are limited to a maximum of 25 to 50 watts.
Because of the cost of shipping full speaker cabinets, value is going to be very dependent upon where you live. If you live in Europe (and specifically the UK) Goodman speakers are valued much higher than in North America. You may find someone willing to pay a premium to get the speaker cabinets intact.
In the US Goodmans were usually privately labelled (sold by someone else) through the 50's and 60's. The relabeling, combined with confusion over interpreting the different Goodman model numbers, has depressed the current market for the speakers in the US.
There are some Goodman models that have a cult following and command big money, but Goodman made a wide range of speakers and most have more modest valuations.
In the US, if the drivers are completely functional (no rips or tears, buzzes, etc) I would ballpark their value at $150 to $200 for the pair. As already mentioned, the cabinets might increase value for a local sale, but might not add any value if the speakers need to be shipped.