OK, my wife is nearly legally blind. She isn't comfortable riding a solo bike. I'm thinking of getting a tandem so she can ride with me. The LBS has what looks like an entry-level Trek with 26" wheels, V-brakes, and suspension seatpost for about $900. Is that a good choice or should I spend more? Since I'm not positive that she'll go for this long-term, would I do better to shop for a used Worksman coaster-brake, single-speed tandem?