kboucher - check the transmission dipstick to verify you have fluid. Not having fluid the transmission can't grab a gear. If the level is fine, then yes, a rebuild is likely the only option.
Most good shops might charge a bit extra, but they can generally finance the cost should you need it for up to a year. You can also contact your financial institution about a line of credit if the interest is decent and you absolutely have no alternatives.
One thing you can ask them is about getting another transmission from a salvage yard. This is of course a mixed bag and the trans can last 10K or 100K without problems. But, the cost is generally a lot less than getting a rebuild. Find a low mileage salvage unit and you should be fine. The only cost will be the trans and labour to change them out.
visit RockAuto Auto Parts
to check parts in your area, or as I mentioned, ask the transmission shop.