Please give some advices where to start with drone build

I want to build a drone, lol.
I want to be an open source software.
Should be cheap, since this is my very first build.
At the end, it should be strong enough to carry everything it need for flying + camera + Raspberry Pi 3 B (it is not mandatory that Pi has been involved in any kind of drone operation).

I am rookie for flight, but I am not noob for Linux and DIY projects. I am not saying that I am some master, but maybe can roughly describe my DIY ability with following link. This is something I made my self, with Google researching, reading tutorials, copy/paste pyhton code examples from internet and editing it according my needs (I am not developer, but has enough knowledge for editing python examples and make it work what I want. Maybe can do it with some other programming language also, IDK didn’t try before):

https://www.reddit.com/r/raspberry_pi/comments/g453rq/my_rpi_lego_nerf_rc_diy_car_spare_time_in_age_of/

Why I decided for PX4? This is something I found on internet that is open source. I don’t know much beside that, this is my first time.
Flight controller - I am in doubt between Pixhawk and Naze32. Why? I don’t know, this is my first time :slight_smile: Just to not make confusion, I am talking here about boards from Aliexpress, where Pixhawk is roughly $35 and Naze32 is about $10 . Yes, I know, these are not genuine boards and quality is here tricky, but as I said, I am fool rokie, this is my first build and I would like to be cheap (I am listening for any kind of suggestion).

Something I saw on PX4 site and it is very cute for me is QAV250 Dev Kit . Searching on Aliexpress for QAV250 is giving me few offers where this kit is coming with Naze32, not Pixhawk and it costs roughly $50 without RC and roughly $100 with Flysky RC. This is one example: https://www.aliexpress.com/item/32840997080.html?spm=a2g0o.productlist.0.0.1f2a3914QxYRW8&algo_pvid=0cd18441-153f-445c-9b98-de85baada325&algo_expid=0cd18441-153f-445c-9b98-de85baada325-13&btsid=0ab6f82215884040738754812e238c&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

First question would be: Is it anything I mentioned above worthy or I am on totally wrong direction? Please take in consideration that this is my first build, want to be cheap and have to start learning somewhere, i.e. on mistakes and steps taken.

One more thing: I searched on Aliexpress cause this is some choice in my country. I have no Amazon in my country, but German Amazon can also be option cause I have friends in Germany who can order this for me and also have lot of friends who traveling very often from my country to Germany and vice versa.

Because of family, kids, and available money in general, I am not able to give $200-$300 straight away, so below would be some plan for the future:

  1. Make quadcopter which simple can fly - if this can be controlled from PC/phone even better, would buy RC later. So I assume that I need body, motors, flight controller, ESCs, wires - something else? Is it my choice described above ok (with Aliexpress QAV250) or you would recommend some other parts to me? Which ones?
  2. Buy RC if this wasn’t mandatory for step 1 - which one?
  3. Buy GPS mouse - which one? (If USB GPS Holux 213 and/or 215 can work with above setup, I already has these)
  4. Buy Camera - not to be worst, but not to be very expensive - which one
  5. Maybe some day in future buy FPV goggles, but this can be ignored for now.

So, I would be very glad if someone of you pro people can recommend some nice configuration for fully beginner, which fits to my above requirement. I know most of you here are pro, but please consider that I maybe not need best components. I would like to be cheap and not totally crap. Yes I know, there is no cheap and god, but maybe some middle.
Please recommend some other flight controller if there is better cheap choice, as I said, I don’t know why I decided for Pixhawk or Naze32
Please give advice if I missed something I need for first flight (only flight, nothing else). From my point of view, I need: Body, motors, flight controller, ESCs, wires and RC

I hope I wasn’t much confused, will be glad to provide any additional info.

Thanks in advance.