I've only built a few paper models - and no paper sailing ships. But I've seen enough of them to be aware that the medium has enormous potential. Some of the things the German and Polish manufacturers do with paper are almost unbelievable. A couple of months ago (or thereabouts) we had a discussion here in the Forum about some photos an H.M.S. Victory that was being built from a paper kit made by a Polish company called Shipyard. That model could stand comparison with the finest scratchbuilt ones - and certainly looked more like the real ship than any of those hideously expensive Italian or Spanish plank-on-bulkhead kits.
One thing that becomes obvious from even a cursory glance: those things aren't for beginners. I've been building models for 49 years, and I wouldn't want to tackle that paper Victory. I have the impression, though, that quite a few more basic subjects are available in paper too.
I've seen some beautiful scratchbuilt models whose builders had used paper models as templates. Plastic sheet is a particularly good material for that purpose; it lends itself to the same construction methods that the paper kit designers use.
I can't resist offering one curmudgeonly caution, though. Balsa wood is pretty generally regarded by experienced ship modelers as the second worst material there is. (The worst: lead.) Quite a few years ago the modeling fraternity got fascinated with balsa, to the point that it became the most common material sold in hobby and craft shops. The truth is that for model builders balsa has one, and only one, real virtue: light weight. For builders of flying model airplanes that's absolutely crucial. For ship modelers it's utterly irrelevant. There's a widespread myth that balsa is "easy to work with." That myth can only have been started by somebody who'd never tried to work with any other kind of wood. I imagine a real expert woodcarver could get acceptable results from balsa, but for novices and most other normal humans the harder woods are easier to work with. Balsa caves in under anything but the sharpest blade, disintegrates when sanded, doesn't bend easily without cracking, dents easily, splits easily, and soaks up finishing materials like a sponge. Some good ship modelers use it occasionally for things like filler blocks in hulls - which won't be visible on the finished model - because it's cheap and easy to find. But most serious scale modelers (with the big exception of the flying aircraft fraternity) regard it with contempt.
Nowadays most decent hobby shops stock basswood in almost as many sizes and shapes as balsa. Basswood isn't the very best modeling wood, but it's capable of doing a good job in most applications. My suggestion to newcomers: forget you ever heard of balsa wood.
That's my rant for this evening. I suspect it may bring some strong contrary opinions; if so - great. But I'm pretty confident in asserting that few serious ship modelers have any use for balsa wood.
One other point. To those of us who can remember buying plastic airplane kits with pocket change, the concept of spending several hundred dollars for a model kit can be pretty jarring. And all of us have to operate within the real limits of our personal and family finances. (I wouldn't mind buying a CalderCraft 1/72-scale H.M.S. Victory, the retail price of which is about $1,000. But with a mortgage, a car payment, medical bills, and a stepkid's student loans in the picture - forget it.) If one considers the money spent on a ship model kit as an investment in leisure-time activity, however, the numbers start to look different. That model that costs $200 or $300 is likely to occupy the builder for 200 or 300 hours - or quite possibly more. Compare the per-hour investment with most other forms of leisure-time activity (video rentals, movies, and professional sporting events, for instance) and model building starts to look like a bargain.
It's not for me to suggest how much money anybody ought to spend on his or her hobby; that needs to be a completely personal decision. But if a modeler can handle a kit that costs $100 or so, he or she ought to ask whether putting up with less-than-the-best merchandise for the sake of saving $30 or $40 is really a good tradeoff.
Just some things to think about. Good luck. It's a great hobby.