The cost of holding on to our previous trailer was relatively low. It was paid for and the storage fee (and insurance) were the only costs to keeping it till it sold. So when we found our Airstream from a private party that was the trigger to sell since we had our summer vacation already planned. Fortunately, it took one day on RV Trader to find a buyer.
We also had a heck of time getting the Airstream titled once we bought it. It took almost 6 weeks and we just got it titled and tagged in our names last week. The previous owner let us use his tags until we got the paperwork laying flat (not something I'd do, not even sure how legal it was even though I had the Airstream insured). I'd have preferred paying to trade at a dealer and avoid all that stomach churn, but there were no models we liked available at the time we were looking.