Professional wood-shop costs easily >$100K :)
Number one cost factor, IMHO, is space for a shop. You need enough room to store and handle lumber. If you have that, you can start with hand tools (saws, chisels, planes) for let's say ~300$. This will in-principle allow you to do everything. People have done this for ages, this way.
Power tools make woodworking much faster. I would start with a jig saw, drill press, circular hand saw. This will be another ~800.
The first expensive mile stone is the table-saw. This will be the most used tool in your shop. Everything gets better when you have access to a good table saw. I have spent 1.2K on mine.
Next upgrades are miter-saw, band saw, planer, jointer. They need a lot of space and are not cheap. This is were you enter the more professional realm.
To get high quality versions of all that tools will cost a lot of money. Oftentimes ebay has used tools for small money. E.g. I bought 15 hand planes for ~100 EUR last year and 50EUR for a used drill press.
Happy woodworking!