External GPU- Help

[PhoenixGamer]

Ok- this is not a common scenario. I recently got a sff desktop, and now want to upgrade it with a video card. I wanted to try an egpu, but they’re SO expensive. My psu isn’t powerful enough for a gpu, so I will need another one. Looking for an external box to use pcie risers to directly attach into my pc.

Problem 1: What box options do I have? I don’t want tb3, only pcie. So like an empty display case, but with enough cooling possibilites not to cook the graphics card. 
Problem 2: PSU. If my card takes too much power, will it overdraw my system? My psu only has like 50 watts left for gpu, and pcie can draw more than that. Will the card take power from an external connector instead of overdrawing my pc? 
Also, I will take graphics card recommendations. Would be cool if I could have it on my desk by the monitor, but that doesn’t matter.

Current PC:

i5 9500 (6 core up to 4.4 ghz)

32 GB RAM

200 W PSU

[Radium_Angel]

33 minutes ago, PhoenixGamer said:

but they’re SO expensive

There is a reason for that. It's specialized hardware for a small market.

34 minutes ago, PhoenixGamer said:

My psu only has like 50 watts left for gpu

You'll need way more power than that.

[Jurrunio]

14 minutes ago, Radium_Angel said:

You'll need way more power than that.

I'm sure he knows he will buy a new PSU regardless

 

but the problem here is that the PSU cant even power the PCIe slot for a graphics card (75w needed) so you need something that allows the PCie slot to be externally powered (SFF PCs dont fit ATX PSUs...), at the same time is PCIe to PCIe for the sake of bandwidth (and cost, as you've figured out). I'm not aware of anything that does both at the same time existing in the market.

[PhoenixGamer]

Could I control the max power draw over pcie somehow?

And yes, I know I will need a PSU. 
Does anyone know a egpu box that will work with a desktop, and a TB3 adapter that works in dell desktops otherwise?

[dizmo]

You're barking up the wrong tree. Give up and go a different route. There are no TB3 cards for you, and an external enclosure really makes no sense. Buy a used case and motherboard, and swap your components over.