I've repaired/sold quite a few over the last couple years, Sony's, Tascams, Teac's, some Revox and Technics etc........ If ya got the right machines with the right options, they go pretty quick. Also, having customers who request certain machines and have them shipped to me for service makes it easy so you don't get stuck with an unwanted unit. You also don't necessarily need to work with just the high end (Pretty ) decks. You can still make a few bucks doing quick services (belts/pinch rollers/caps/pots/clean/lube). Some are real easy to service, some are a MOFO to do, ya just got to pick your battles. Is the market SOFT on RTR's....... Not even close.
As for shipping, I've shipped a bunch (as I have with WOPL's) and have not lost a single one.... There is a trick to it it. But you charge the customer separately for shipping a rtr. Between double boxing, bubble wrap (the small bubbles) and the pink sheets of insulation, tape and the actual shipping weight and insurance, it can add up quick. I charge (the first invoice) for parts/service, the second invoice will cover labor and incidentals, and the last will cover transport/shipping/supplies/insurance. I do it this way so I don't get stuck paying for parts. Plus, it hurts the customers wallet less if he gets 3 pay periods to not freak out and he can keep the shipping and insurance separate from necessities....
Stay away from units that need SERIOUS work unless you have the tools to do it. I just paid $320 for alignment tapes and shipping. Luckily, I passed this on to the customer. When it comes to setting/checking torque values, you may NOT even find the correct tools to do it so HELP your customer pick out a suitable machine that is in the nicest machine (condition wise for resale) and these TEND to be the easiest to service and return to factory fresh shape op's wise. Shop wisely and it's not hard to find a machine that has spent 20 years in a box in the closet that needs an easy service and some belts that looks near new. I just did it a week ago. Be careful who you ask for help or questions..... There are a few who will tell you you can't do it, you can't do it right, it's my way or the highway, or, that talk way over your head, have repair waiting lists longer than 6 months, tells you that everybody is fucked up and is doing it wrong even if you follow the manual, and read their "Know it all Posts", they are easy to pick out. Good luck.
P