TubeNet

are there any good places to completely rebuild a trashed tuba. i might find a way to obtain a good tuba in terrible condition. it would need overhauled valves, and replacement slides. also, about how much would that cost?

There are plenty of shops that will rebuild a tuba to your specifications. It would be impossible to give you even a ballpark price without seeing the horn and speaking with you. A complete rebuild on a Miraphone might cost upwards of $3000. A play condition on an old beater might cost as little as $250.

You might chack with these folks...

http://www.napbirt.org/schools/Badger.htm

Sure, a good-quality tuba can be completely restored, but there's no telling exactly how much work or expense will be involved without carefully examining the instrument, and even then, I find that there can be hidden problems that do not surface until the instrument is apart and in the process of restoration.
The valveset is the heart of the instrument, and if the valves on an instrument are not readily re-buildable, then you have a parts horn. If the instrument in question is not currently in production, any replaced tuning slides must be built from scratch (if you're lucky), and that takes a lot of time, too.
Badger State Repair, of Elkhorn, Wisconsin, does a good and thorough job of completely restoring instruments, and they have full lacquering and plating capabilities. Their piston valve restoration is amongst the best in the business.
Depending upon the instrument and condition, a tuba restoration to like-new appearance and performance can cost anywhere from $2,800.00 to over $5,000.00, but you get what you pay for.