Forum rules
This forum is for buying or selling your personal equipment. Sponsored selling is allowed as well. All ads are required to have the following information: Price (even for trades), brand, model, and location (City and State, for instruments, not accessories). It is acceptable to link to an external ad if you are promoting a sale of your personal equipment. No Ebay auctions, but "Buy It Now" listings are fine. Photos are HIGHLY suggested as well, and may be hosted on Google Drive, or elsewhere. If you see an ad that does not meet these criteria, please report it.
The people who are probably most interested are on TubeNet, so why don't you just ask for bids via email and take the best received if you are satisfied?
Just an idea
Remember the tuba is only worth what people are willing to pay!
I have always found that consignments at Dillon's are the best way to sell horns. They get you a great price for the horn and you have the advantage of advertising on their website.