As others have said, 8x10 at that price is going to be challenging. I have *no* idea what is and isn't available in Pakistan, though---in the States the cheapest options are the many early-20th-century wood cameras by American manufacturers (Eastman, Seneca, and so on), and I suppose you could buy internationally, but they're bulky and heavy and shipping will be a nasty additional expense.

I find that lenses actually aren't too bad. My go-to lenses are a 215/4.8 Ilex Acuton, for which I think I paid about $100 in shutter on eBay, and a 270mm G-Claron. Older and theoretically-inferior lenses work just fine in larger formats---I suppose you're familiar with this from 4x5, and it only gets more so as the size goes up.

Film holders sometimes go cheaply on here or from used equipment dealers, but they're still a whole lot more expensive than 4x5 holders.

X-ray film is a cheap option for experimental shooting; most people wouldn't want to use it as their primary medium for serious work.

Tripod stability becomes a big deal. Again, I don't know what's available in Pakistan, but here it's not too hard to find BIG heavy (inconvenient) tripods for cheap from private sellers; my Majestic cost me US$50 (thanks to a fellow member here who found it for me), and it will hold anything, but you need a team of mules to move the tripod itself from place to place!

These costs add up, so it doesn't take much to exceed US$300. You may end up needing to buy piece by piece over time.