I am a total beginner to pcb design. I have a schematic in KiCad 7.0 and I want to make a PCB for it. In one of the KiCad forums, PCBWay was recommended as a low cost PCB fabricator, and the prices looked OK. I created a 2 layer board, but it is too big for my needs, so I started to design a 4 layer board - inner layers are power and ground, and the outer layers are signals. I have a handful of signals left to add, and I need to run some signals on both layers so I can cross tracks - i.e. start on the front, jump to the back, then jump to the front and connect the signal. I was reading about vias and plated/un-plated holes and have managed to confuse myself. The cost of a board with blind/buried vias is 8-10 times the cost of a standard board from PCBWay. Do I need to use a via, or can I achieve what I want with a through board hole?