The same identical uke will always cost more with a pickup because, of course, the pickup costs money (a really decent one can cost a good $150). On a guitar, the pickup makes minimal if any difference to the unamplified sound, but on a uke, it makes more of a distance simply because the box of electronics takes a greater percentage of the space in the body. I can't say for sure how much difference it makes to the acoustic tone, but on the one hand, I've played electro-acoustic ukes that sounded fine unplugged, but on the other hand, I played a Hamano soprano with a pickup which was very quiet unplugged, whereas people on the Cosmos say that Hamanos are if anything quite loud normally. YMMV.