Hi Spartan,
I do agree with several posters, repairing the camera will cost more than replacement. You should be able to pick up a replacement k1000 for under $50 (these bodies are abundant and many people sell off their kit cheap to clear closet space. If you a few k mount lenses I would suggest picking up a new body cheap at some point. If you plan to develop your own black and white I would lean this with 35mm as it is easier to roll and cheaper to shoot.
If your interested in going into medium format I would determinately encourage it. You mentioned you primarily do portraiture and landscape. I like a few others would suggest a 67 over a 645 in such a case. The 67 will be larger negatives, a heavier camera, but also as others noted a cheaper system as the 67 lenses can be be picked up for really inexpensive prices if you shop around and wait. The 67 can be handheld at a fast shutter and true the 645 would lend more to street photography type shooting, but you indicated portraiture and landscape as primary functions so I imagine you would be using a tripod pretty heavily(id leave the portability to k30 or the k1000). Both bodies have 3 generations of age 645,645n 645nII & 6x7, 67, 67II do some research on models so you know the pros and cons, plenty of people on the forum can help with debating which to buy when your ready to make the purchase. I'd suggest maybe getting a early one cheap that has some wear on it then upgrade to the 67II when you can afford it if start to invest in the system. Given what you shoot maybe get a 45mm or 55mm and a 165mm or 200mm to start for the 67.
You'll probably end up send rolls in to be processed if you shoot 120, especially if you shoot transparency film, which trust me you will
And you'll want to get access to a good film scanner, probably through the local college unless you want to spend some money on your own.
You could also pick up a Holga while your saving up and start dabbling in medium format that way.