>>4415679You can do basic astro with justa tripod and a DSLR with no tracking. Just take exposures of around 600/f seconds and collect enough data for 20-30 mins of exposure, then stack them in something like DeepSkyStacker. That's how I got in.
If you want deep space objects, a mount is a must. Mounts are of two types - basic ones for visual, so-called Az-Alt, and more complex ones for photos, equatorial. Some crazy folks try to take photos with hand-operated EQ mounts, and it's possible. The most basic mounts which are designed to carry a DSLR on top are pretty cheap at maybe 400-500 bucks, but they are unable to take all but the lightest scopes.
Recently mounts have undergone a revolution with the wide adoption of strain wave reductors instead of old worm gears, allowing high load capacity in a light and simple to use package. Most high-capacity mounts are harmonic ones now.
The bare minimum kit for actual proper astrophotography is a go-to mount, a scope and a DSLR. You can get a mount for 1000-1200 bucks like the ZWO AM3, get a simple refractor or the godly kit that's SW Quattro 150p for another $450, and then you're done. If you want to be fancier, you can swap from a DSLR and to a dedicated camera and a control computer (ASIAir/equivalent or mini pc with NINA) for another 800 bucks. Your final upgrade is a guidescope with a guide camera for ~$300.
Once aperture fever sets in, consider yourself lost. You'll waste thousands of dollars on high-capacity mounts, expensive large telsecopes, dew heaters, filters and filter wheels, monochrome cameras and the horror that is quality refractors. And you won't have any fun either since the weather is shit. The more you spend, the more miserable you'll get, so don't even start.