Not much really, as I buy singles of my plants and propagate them in nursery tanks, and trade plants with local fish keepers, and trade plants to stores in town.
My plants in my 50g came from the following.
4.99 java moss, was a golf ball sized clump when I first bought it.
9.99 riccia, small clump tied to a piece of slate
1.99 ludwigia repens, bought one single stem (now have 100s of stems in my tanks)
4.99 Eleocharis parvula
4.99 Echinodorus tenellus
2.99 anubis
free cabomba, and crypts traded some plants to a fish store
java fern and lace java fern I got from a local fish keeper I traded some plants with.
around 3 bucks for a bulb of the Nuphar stellata.
c02 I ended up paying 150.00 (5lbs tank and reg and solenoid) for after store credit from trading in plants. I had been growing them
DIY c02 until that point in 29g tanks.
I had originally spent about 50 bucks in plants when I first started them out, now I just trade locally if there is any thing new I want to try.