It's gonna be really hard to find a mechanical keyboard at 30aud, that's so cheap to the point where the only other options are cheap 10 dollar membrane keyboards, so that might be to much to ask in terms of everything you wanted.
The only boards I can find for under 30 are these mechanical keyboards from Kmart that I saw in a youtube video once. They have blue clicky switches and you can disable the rgb from what I'm aware
https://www.kmart.com.au/product/mini-mechanical-gaming-keyboard-43099771/https://www.kmart.com.au/product/mechanical-backlit-gaming-keyboard-42959588/ (keep in mind this one is on clearance and originally is 39)
Reds as you describe are linear switches (where the keyswitch press is consistent from top to bottom) and linear switches are a preference thing that you will need to try in person to understand your preference completely so if you have a friend who owns a linear switch keyboard ask them to type on it but if you don't you can just jump in but you might not like them. Keep in mind some red switches may not be linear so you will need to check beforehand.
If you can I would say to save up like 150-180 aud (I know that might be a lot for you) and buy something like a Keychron K8 Pro (I know it's not white but it is good, and you could always buy something else that fits what you want). You pay a lot more for a lot better product, and it has linear, tactile or clicky switches but you made not be in the financial position to afford that, so there is always the keyboard at kmart.
hope this helps!