are you looking to buy all your stone and driftwood and rock or are you going to collect it from areas near you. a good way to not spend a lot of money on plants is to buy them in them from people on this website. to fill a 10g i would estimate abou $50 in plants. also it depends on your substrate type. sand or aquasoil?
My first planted tank (or just aquarium) was a 10 gallon I had back in college.
Go low-tech, it will be less cost and less maintenance.
Anyways, in my initial set up, I just stuck a couple daylight compact flourescent bulbs in the hood, used kitty litter (may have thrown some peat and vermiculite in the bottom, I can't remember), and a HOB filter (I think it was a tetra/whisper at the time, but I later switched to an aquaclear, and liked that better).
SafeTSorb sounds like it's a bit better then kitty litter, and it looks a lot nicer.
the hardscape is probably going to be the next most expensive thing after the plants. If you go out hiking in the hills and such near vegas, you may be able to find some pretty weathered wood, but that's pretty hit or miss.
10g tank 10-15$
Cfl clamp on 15$
Led floodlight 10-20$ on evilbay
Fish could cost any where from 5$ and up to fill it
White cloud mtn minnows are 4/1.00$ at my Lfs you could easily put 20 in a 10g
Plants all depend on what you get.
Have enough light and maybe some DIY co2 you could just buy a couple plants to start, then trim and replant as you go
For soil a 20$ bag of Eco complete would be more than enough to fill the tank
+\- 100$ you can have a nice planted tank.
50 gallon tank
You can buy a tank for 20+ used or new is around 100
You need good water movement so I would recommend multiple hob's or a powerhead if you don't have the money for a high powered canister
You can get a filter for around 40$ and a powerhead for about the same
A heater will be 20+
Plants are goin to cost an arm an leg of you want to buy everything right off.
For substrate you could use miracle grow organic potting mix w/a sand cap for less than 20$ to do the whole tank
As far as co2 and lighting goes I would go low tech if you're trying to do a tank that large on a budget get a couple 2 bulb t8 shop fixtures for light and some 6500k bulbs from home depot. It will be about 60$ for bulbs and fixtures
This does not include maintenance cost such as ferts, food, water conditioner, etc.